Liquid ejection head

Abstract

To provide a liquid discharge head which has a good coating state of a second sealing resin.SOLUTION: A liquid discharge head includes a flexible film wiring board formed with an opening, a plurality of discharge element substrates each of which has a discharge port surface provided with a discharge port for discharging liquid and is aligned in a predetermined direction in the opening, a lead electrode group which is arrangement of a plurality of lead electrodes aligned in the predetermined direction in the opening, is provided on the flexible film wiring board for each of the discharge element substrates and is connected to the discharge element substrates, a dummy lead provided between the mutually adjacent lead electrode groups, a first sealing resin provided around the discharge element substrates, and a second sealing resin provided on the upper layer side of the first sealing resin so as to cover the lead electrodes and the dummy lead, wherein the dummy lead reaches a gap between the mutually adjacent discharge element substrates in the case of viewed in a direction perpendicular to the discharge port surfaces of the discharge element substrates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head that ejects liquid. [Background technology]

[0002] In a flexible film wiring board (wiring film) in a liquid ejection head such as an ink jet recording head, the electrical connection portions are covered with a sealant. Fig. 12 is a schematic diagram showing a conventional ink jet recording head.

[0003] In FIG. 12, the recording element substrate 1 (each of the recording element substrates 1a and 1b) as an ejection element substrate has a plurality of ejection energy generating elements (not shown) that apply ejection energy to the recording liquid. The recording element substrate 1 also has a plurality of ejection ports 6 formed therein for ejecting the recording liquid (liquid). The recording liquid is ejected from the ejection ports 6 by pressure generated by the ejection energy. A support member 8 is a member to which a plurality of recording element substrates 1 are adhesively fixed in parallel. A flexible film wiring substrate 11 is electrically connected to the recording element substrate 1 and has a plurality of wires (not shown) for transmitting electrical signals from the recording apparatus main body (not shown) to the recording element substrate 1, as well as a wire protection layer for protecting the plurality of wires. A support plate 9 is adhesively fixed to the support member 8 and holds and fixes the flexible film wiring substrate 11. A first sealing resin 18 seals the periphery of the recording element substrate 1 and some of the electrode pads 7 provided on the recording element substrate 1 to protect them from corrosion and short-circuiting due to the recording liquid. The second sealing resin 19 also covers the electrical connection portions between the electrode pads 7 provided on the recording element substrate 1 and the lead electrodes 13 provided on the flexible film wiring substrate 11, as well as the dummy leads 17, to protect them from external forces such as corrosion by the recording liquid and wiping. In Fig. 12, the second sealing resin 19 is shown by dashed lines to show the electrode pads 7 and the lead electrodes 13, and the second sealing resin 19 may also be shown by dashed lines in similar figures described below.

[0004] In the liquid ejection head disclosed in Patent Document 1, as shown in FIG. 12, dummy leads 17 are provided adjacent to a group of lead electrodes (plurality of lead electrodes 13) connected to a recording element substrate 1. The dummy leads 17 extend shorter than the lead electrodes 13 and are not connected to the electrode pads 7. Such dummy leads 17 can narrow the space (gap) at the inner periphery (edge) of the opening 12 (device hole) of the flexible film wiring substrate 11. They can also narrow the space between the group of lead electrodes connected to the recording element substrate 1a and the group of lead electrodes connected to the recording element substrate 1b. This prevents the second sealing resin 19 from falling into these spaces (gaps), and prevents deterioration of the condition in which the second sealing resin 19 covers the electrical connections between the electrode pads 7 and the lead electrodes 13. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-255866 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology, the electrical connection portions are not covered well by the second sealing resin 19, which may result in a decrease in the reliability of the electrical connection portions. For example, if the second sealing resin 19 is applied in a state where the first sealing resin 18 has not flowed sufficiently between the adjacent recording element substrates 1a and 1b, the first sealing resin 18 may flow between the recording element substrates 1a and 1b when it is cured by heating after application. In the conventional technology, The resin 19 is provided directly on the first sealing resin 18. Therefore, when the first sealing resin 18 flows between the recording element substrates 1a and 1b, the second sealing resin 19 is also pulled and may fall into the gap between the recording element substrates 1a and 1b. If the second sealing resin 19 falls into the gap between the recording element substrates 1a and 1b, the covering condition of the electrode pads 7 with the second sealing resin 19 may become poor, and the reliability of the electrical connections may be reduced.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid ejection head in which the second sealing resin is well coated. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, a liquid ejection head of the present invention includes a flexible film wiring board having an opening formed therein, and an ejection port surface on which an ejection port for ejecting liquid is provided, and includes a plurality of ejection element substrates arranged in a predetermined direction within the opening, and a collection of a plurality of lead electrodes arranged in the predetermined direction within the opening, the plurality of lead electrodes being provided on the flexible film wiring board for each of the ejection element substrates and connected to the ejection element substrate, dummy leads being provided between adjacent groups of lead electrodes, a first sealing resin provided around the ejection element substrate, and a second sealing resin provided on an upper side than the first sealing resin so as to cover the lead electrodes and the dummy leads, and the dummy leads reach gaps between the adjacent ejection element substrates when viewed in a direction perpendicular to the ejection port surface of the ejection element substrates. When the distance between adjacent lead electrodes is P and the distance between the dummy lead and the lead electrode adjacent to the dummy lead is P', the relationship is 0.75P≦P'≦1.25P. It is characterized by: [Effects of the Invention]

[0009] The present invention can provide a liquid ejection head in which the second sealing resin is well coated. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a liquid ejection head according to a first embodiment of the present invention. [Figure 2]FIG. 2 is a cross-sectional view of a portion where the lead electrodes in FIG. 1 are arranged. [Figure 3] FIG. 3 is a schematic view showing a filling state of a first sealing resin and a second sealing resin. [Figure 4] 1 is a cross-sectional view illustrating the effect of the present invention. [Figure 5] FIG. 4 is a schematic diagram showing a liquid ejection head according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram showing a liquid ejection head according to a third embodiment of the present invention. [Figure 7] FIG. 10 is a schematic diagram showing a liquid ejection head according to a fourth embodiment of the present invention. [Figure 8] 1 is a perspective view showing a liquid ejection head according to the present invention. [Figure 9] 9 is a cross-sectional view taken along the line AA in FIG. 8. [Figure 10] 9 is a cross-sectional view of FIG. 8 taken along line BB. [Figure 11] FIG. 1 is a perspective view showing a recording head cartridge according to the present invention. [Figure 12] FIG. 1 is a schematic diagram showing a conventional liquid ejection head. [Figure 13] 1 is a cross-sectional view for explaining a problem to be solved by the present invention. [Figure 14] FIG. 13 is a cross-sectional view of a portion where the lead electrodes in FIG. 12 are arranged. [Figure 15] 1 is a cross-sectional view for explaining a problem to be solved by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] 1 is a schematic diagram showing a liquid ejection head according to a first embodiment of the present invention as viewed from above. In the first embodiment, two recording element substrates 1 (recording element substrates 1a and 1b) serving as two ejection element substrates are arranged on a support member 8. The number of recording element substrates 1 is not limited to two, and may be three or more.

[0013] In FIG. 1, the recording element substrate 1 (each of the recording element substrates 1a and 1b) has a plurality of ejection energy generating elements (not shown) that apply ejection energy to the recording liquid (liquid). The recording element substrate 1 also has a plurality of ejection ports 6 formed therein for ejecting the recording liquid. The recording liquid is ejected from the ejection ports 6 by pressure generated by the ejection energy. The support member 8 is a member to which the plurality of recording element substrates 1 are adhesively fixed. The flexible film wiring substrate 11 is electrically connected to the recording element substrate 1 and has a plurality of wires (not shown) for transmitting electrical signals from the recording apparatus main body (not shown) to the recording element substrate 1, as well as a wire protection layer for protecting the plurality of wires. The support plate 9 is adhesively fixed to the support member 8 and holds and fixes the flexible film wiring substrate 11. The first sealing resin 18 seals the periphery of the recording element substrate 1 and some of the electrode pads 7 provided on the recording element substrate 1 to protect them from corrosion and short-circuiting due to the recording liquid. Furthermore, the first sealing resin 18 is also applied to the outer periphery of the flexible film wiring substrate 11 to protect the wiring and other components of the flexible film wiring substrate 11 from corrosion by the recording liquid. The second sealing resin 19 covers the electrical connections between the electrode pads 7 on the recording element substrate 1 and the lead electrodes 13 on the flexible film wiring substrate 11, as well as the dummy leads 17, to protect them from corrosion by the recording liquid and external forces such as wiping. That is, the second sealing resin 19 covers the electrode pads 7, the lead electrodes 13, and the dummy leads 17. The second sealing resin 19 is applied after the first sealing resin 18 and is provided above the first sealing resin 18. Materials are selected for the first sealing resin 18 and the second sealing resin 19 according to their respective applications. For example, a low-viscosity material that easily wraps around the periphery of the recording element substrate 1 is selected for the first sealing resin 18. For the second sealing resin 19, a material is selected that has high thixotropy to more reliably cover the lead electrodes 13 and that becomes very hard after curing so that it can withstand external forces such as wiping.

[0014] In the first embodiment, an opening 12 (device hole) exposing the recording element substrate 1 is formed in the flexible film wiring substrate 11. An opening (not shown) similar to the opening 12 is also formed in the support plate 9. A plurality of electrode pads 7 are provided on the recording element substrate 1 at predetermined intervals (desired intervals), and a plurality of lead electrodes 13 electrically connected to the plurality of electrode pads 7 are provided at predetermined intervals within these openings. The arrangement direction of the recording element substrates 1a and 1b and the arrangement direction of the plurality of lead electrodes 13 are both predetermined directions along the sides of the openings (such as the opening 12). In addition, there is a region between the adjacent recording element substrates 1a and 1b where the lead electrodes 13 are not provided, which is wider than the predetermined interval. Dummy leads 17 are added in this region so that the interval between the dummy leads 17 and the lead electrodes 13 adjacent to the dummy leads 17 is the predetermined interval. This allows all leads, including the lead electrodes 13 and the dummy leads 17, to be arranged at the predetermined intervals (the same intervals). The dummy leads 17 are provided, for example, on the flexible film wiring board 11. The dummy leads 17 are provided adjacent to the lead electrode group (plurality of lead electrodes 13) connected to the recording element substrate 1 in the predetermined direction.

[0015] As shown in FIG. 1, the second sealing resin 19 is applied so as to completely cover the area including the electrical connection portions between the electrode pads 7 of the recording element substrate 1 and the lead electrodes 13 of the flexible film wiring substrate 11, and the dummy leads 17. In this manner, as shown in FIG. 2 (a cross section along the plurality of electrode pads 7), the first sealing resin 18 applied to the outer periphery of the recording element substrate 1 fills every corner below the lead electrodes 13 and the dummy leads 17 due to capillary action. Furthermore, between adjacent lead electrodes 13, the first sealing resin 18 is pulled up to the height of the lead electrodes 13 and the dummy leads 17 due to surface tension. At this time, the first sealing resin 18 sinks under its own weight so that the center between the lead electrodes 13 is its lowest point. Between adjacent lead electrodes 13 and dummy leads 17, the first sealing resin 18 is also pulled up to the height of the lead electrodes 13 and the dummy leads 17 due to surface tension, just as between the lead electrodes 13. Then, the first sealing resin 18 is pressed against the lead electrodes 13 and the dummy electrodes by its own weight. The first sealing resin 18 and the second sealing resin 19 applied thereon are in close contact with each other. The amount of sagging of the first sealing resin 18 is determined by the viscosity of the resin and the spacing between the leads (lead electrodes 13 and dummy leads 17). Generally, if all the leads are arranged at predetermined intervals (the same spacing), the sagging of the first sealing resin 18 does not pose a problem.

[0016] The first sealing resin 18 also fills the gap between the adjacent recording element substrates 1a and 1b due to capillary action. However, as shown in FIGS. 3(a) and 3(b), depending on the condition (width, wettability) between the recording element substrates 1a and 1b and the viscosity of the first sealing resin 18, the first sealing resin 18 may not completely fill the gap between the recording element substrates 1a and 1b even after the second sealing resin 19 is applied. FIG. 3(a) shows the state before the second sealing resin 19 is applied, and FIG. 3(b) shows the state after the second sealing resin 19 has been applied. After the second sealing resin 19 is applied, the sealing resin (first sealing resin 18 and second sealing resin 19) is heat-cured. During the temperature rise, the viscosity of the sealing resin temporarily decreases, and the fluidity of the sealing resin increases. 3(b), the sealing resin may flow again between the recording element substrates 1a and 1b before hardening of the first sealing resin 18. In the first embodiment, the distance (gap) between the adjacent recording element substrates 1a and 1b is set to 110 μm, and the variation in this distance due to the dimensional accuracy of the recording element substrate 1 and the fixing accuracy of the recording element substrate 1 is set to ±20 μm.

[0017] When the dummy leads 17 are short as in the conventional technology (FIG. 12), the second sealing resin 19 is supported by the first sealing resin 18 in the gap between the adjacent recording element substrates 1a and 1b, as shown in FIG. 13(a). Therefore, if the first sealing resin 18 flows during curing, the second sealing resin 19 may also be pulled and fall into the gap between the recording element substrates 1a and 1b, as shown in FIG. 13(b). If the second sealing resin 19 falls into the gap between the recording element substrates 1a and 1b, the covering state of the second sealing resin 19 changes from the state shown in FIG. 14 to the state shown in FIG. 15. For example, the amount of the second sealing resin 19 covering the dummy leads 17 and the amount of the second sealing resin 19 covering the electrode pads 7 closest to the gap between the adjacent recording element substrates 1a and 1b may be significantly reduced.

[0018] Therefore, in the first embodiment, when viewed in a direction perpendicular to the ejection port surface on which the ejection ports 6 of the recording element substrate 1 are provided, the dummy leads 17 are configured to reach the gap between the adjacent recording element substrates 1a and 1b. For example, as shown in FIG. 3A, the length of the dummy leads 17 is set to be approximately equal to the length of the lead electrodes 13, so that the dummy leads 17 extend into the gap between the adjacent recording element substrates 1a and 1b. From the viewpoint of electrical reliability, it is preferable that the distance from the end of the dummy leads 17 to the end of the area covered by the second sealing resin 19 be 0.1 mm or more. The length of the dummy leads 17 may be longer or shorter than the length of the lead electrodes 13. In the first embodiment, the length of the lead electrodes 13 is set to 560 μm, and the length of the dummy leads 17 is also set to 560 μm.

[0019] By making the length of the dummy leads 17 longer than in the past, the area where the second sealing resin 19 and the first sealing resin 18 come into contact with each other can be made smaller than in the past, and the shape of the second sealing resin 19 on the dummy leads 17, the electrode pads 7, etc. can be maintained. In other words, the amount of the second sealing resin 19 covering the dummy leads 17 and the amount of the second sealing resin 19 covering the electrode pads 7 closest to the gap between the adjacent recording element substrates 1a and 1b can be maintained. For example, as shown in FIG. 4(a), in the gap between the adjacent recording element substrates 1a and 1b, most of the second sealing resin 19 is supported by the dummy leads 17, and the area where the second sealing resin 19 comes into contact with the first sealing resin 18 is small. Therefore, even if the first sealing resin 18 flows when curing the sealing resin, the second sealing resin 19 does not fall into the space between the recording element substrates 1a and 1b to a great extent, as shown in FIG. 4(b), and the covering state of the second sealing resin 19 does not change significantly from the good state shown in FIG. 2.

[0020] In this way, in the first embodiment, by making the area where the second sealing resin 19 and the first sealing resin 18 come into contact smaller than in the past, it is possible to prevent the second sealing resin 19 from being significantly depressed due to the flow of the first sealing resin 18. Consequently, the second sealing resin 19 can cover a desired area in an appropriate manner (for example, in a uniform shape).

[0021] Furthermore, in the first embodiment, in order to align the spacing between all the leads, including the lead electrodes 13 and the dummy leads 17, the width of the dummy leads 17 is made larger than the width of the lead electrodes 13. Therefore, the area where the dummy leads 17 exist is large, extending from between the recording element substrates 1a and 1b to the flexible film wiring substrate 11. This also makes it possible to reduce the area where the second sealing resin 19 and the first sealing resin 18 come into contact with each other, thereby suppressing deformation (sagging) of the second sealing resin 19 due to the flow of the first sealing resin 18.

[0022] Furthermore, in the first embodiment, the dummy leads 17 are fixed to the recording element substrate 1, similar to the lead electrodes 13. For example, as shown in FIG. 3(a), the dummy leads 17 are fixed to both of the adjacent recording element substrates 1a and 1b. This makes it possible to suppress warping or bending of the dummy leads 17, and to prevent the dummy leads 17 from being exposed from the second sealing resin 19 due to warping or bending of the dummy leads 17. Furthermore, the height of the base portion on which the second sealing resin 19 is applied can be made uniform, and the shape of the second sealing resin 19 can be stabilized.

[0023] There is no particular limitation on the method for fixing the dummy leads 17. For example, a pad portion that is not an electrode may be provided on the recording element substrate 1, and the dummy leads 17 may be fixed to the pad portion. Alternatively, an electrode pad that enables the dummy leads 17 to be used as common electrical wiring for multiple recording element substrates 1 may be provided on the recording element substrate 1, and the dummy leads 17 may be electrically connected to the electrode pad.

[0024] Furthermore, although all the leads including the lead electrodes 13 and dummy leads 17 are arranged at substantially equal intervals (approximately equal intervals), the lead intervals may be made uneven as long as the above-mentioned depression (sinking) of the second sealing resin 19 does not occur. However, if the interval between adjacent lead electrodes 13 is P and the interval between the dummy lead 17 and the lead electrode 13 (the lead electrode 13 adjacent to the dummy lead 17) is P', it is preferable that 0.75P≦P'≦1.25P.

[0025] Furthermore, if the lead electrodes 13 and the dummy leads 17 are made of the same material, they can be formed in the same process when manufacturing the flexible film wiring board 11. This allows the liquid ejection head to be manufactured with fewer steps, thereby reducing the cost associated with manufacturing the liquid ejection head.

[0026] 1. The shape of the dummy leads 17 may be any shape as long as it is possible to suppress deformation (sagging) of the second sealing resin 19 due to the flow of the first sealing resin 18. For example, as shown in FIGS. 5 and 6, the width of the dummy leads 17 on the flexible film wiring board 11 side may be smaller than the width of the dummy leads 17 on the gap side between the adjacent recording element substrates 1a and 1b.

[0027] 5 is a schematic diagram showing a liquid ejection head according to a second embodiment of the present invention, as viewed from above. The second embodiment is the same as the first embodiment, except for the arrangement of the electrode pads 7 on the recording element substrate 1 and the shape of the dummy leads 17.

[0028] As shown in FIG. 5 , in the second embodiment, the electrode pads 7 (the electrode pads 7 to which the lead electrodes 13 are respectively connected) on the recording element substrate 1 are closer to the adjacent recording element substrate 1 than in the first embodiment. The arrangement of the lead electrodes 13 is also changed in the same way as the arrangement of the electrode pads 7. Therefore, the distance between the lead electrodes connected to the recording element substrate 1a and the lead electrodes connected to the recording element substrate 1b is narrower than in the first embodiment. In such a case, if the shape and fixing method of the dummy leads 17 are the same as in the first embodiment, the distance between the dummy leads 17 and the lead electrodes 13 (the lead electrodes 13 adjacent to the dummy leads 17) would be significantly different from the distance between the adjacent lead electrodes 13. Therefore, in the second embodiment, the shape of the dummy leads 17 is T-shaped so that all the leads, including the lead electrodes 13 and the dummy leads 17, are substantially equally spaced. In the second embodiment, as in the first embodiment, the dummy leads 17 are fixed to both the adjacent recording element substrates 1a and 1b.

[0029] Fig. 6 is a schematic diagram showing a liquid ejection head according to a third embodiment of the present invention, viewed from above. As shown in Fig. 6, in the third embodiment, the dummy leads 17 have an L-shape and are fixed to one of the adjacent recording element substrates 1a, 1b (recording element substrate 1b in Fig. 6). This configuration can be suitably adopted, for example, in cases where there is space to fix the dummy leads 17 only on one of the recording element substrates 1a, 1b.

[0030] FIG. 7 is a schematic diagram of a liquid ejection head according to a fourth embodiment of the present invention, viewed from above. In the fourth embodiment, the contours and fixing method of the dummy leads 17 are the same as those in the first embodiment. However, in the fourth embodiment, openings are formed in the dummy leads 17 in a direction substantially perpendicular to the recording element substrate 1. That is, openings are formed in the dummy leads 17 that penetrate from a first surface of the dummy leads 17 on the ejection port side of the recording element substrate 1 to a second surface of the dummy leads 17, which is the reverse side of the first surface. This allows air to escape from the dummy leads 17 when filling the underside of the dummy leads 17 with the first sealing resin 18, making it easy to fill the underside of the dummy leads 17 with the first sealing resin 18. It is preferable that the area where the dummy leads 17 support the second sealing resin 19 in the gap between the adjacent recording element substrates 1a and 1b be large. Therefore, when viewed in a direction perpendicular to the recording element substrates 1a and 1b (a direction perpendicular to the ejection port surfaces of the recording element substrates 1a and 1b), it is preferable that the above-mentioned openings be formed at a position offset from the gap between the recording element substrates 1a and 1b.

[0031] Next, the overall configuration of the liquid ejection head according to the present invention will be described with reference to Figures 8 to 10. Figure 8 is an external perspective view, Figure 9 is a cross-sectional view taken along line AA in Figure 8, and Figure 10 is a cross-sectional view taken along line BB in Figure 8.

[0032] As shown in FIG. 8, the liquid ejection head according to the present invention is composed of a member including a plurality of recording element substrates 1 of different shapes and sizes, a support member 8, and a flexible film wiring substrate 11. Here, for convenience, an example in which the plurality of recording element substrates 1 are two recording element substrates 1a and 1b will be described. A plurality of ejection ports 6 for ejecting recording liquid are formed in an ejection port plate 5 on the front side of each recording element substrate 1, corresponding to a plurality of ejection energy generating elements 4 (e.g., a plurality of electrothermal converting elements). A recording liquid supply port 3 is formed in a support member 8 on the back side of the recording element substrate 1, penetrating the ejection port 6 for supplying recording liquid. A plurality of electrode pads 7 electrically connected to the plurality of ejection energy generating elements 4 are provided on both ends of the recording element substrate 1. Each electrode pad 7 is provided with a stud bump 14 (gold bump) made of gold wire. Note that solder bumps or plated bumps other than stud bumps may also be provided. The recording element substrates 1 are disposed adjacent to each other on the support member 8 and adhesively fixed in place with high precision on the order of several μm to several tens of μm. 9 and 10, only a few discharge ports 6 are shown as an example, but in an actual product, tens to hundreds of discharge ports 6 are formed. Similarly, in an actual product, tens to hundreds of electrode pads 7 are also provided.

[0033] An opening 12 is provided in the flexible film wiring substrate 11 to expose the two recording element substrates 1a and 1b. To electrically mount the two recording element substrates 1a and 1b, a plurality of lead electrodes 13 are provided around the opening 12. The lead electrodes 13 are electrically connected to the electrode pads 7 on the recording element substrates 1a and 1b in a one-to-one relationship. The lead electrodes 13 are electrically connected to the electrode pads 7 via stud bumps 14. For example, the stud bumps 14 on the electrode pads 7 are brought into contact with gold-plated lead electrodes provided on the flexible film wiring substrate 11, and while the contact area is heated to 150 to 200°C, a desired load and ultrasonic vibration are applied to the contact area for a predetermined period of time. This induces intermetallic bonding at the contact area, electrically connecting the lead electrodes 13 to the electrode pads 7. The method for connecting the lead electrodes 13 to the electrode pads 7 is not limited to the single-point bonding described above. For example, the lead electrodes 13 may be connected to the electrode pads 7 collectively by gang bonding using a thermocompression bonding unit. Any method may be used to connect the lead electrodes 13 to the electrode pads 7, such as a reflow method for melting solder bumps, wire bonding for connecting corresponding electrodes with wires, or an ACF connection method. Similar to the lead electrodes 13, dummy leads 17 are also provided around the openings 12.

[0034] The flexible film wiring board 11 is bonded and fixed to the support plate 9 so as to completely cover the support plate 9 and protrude a predetermined amount like a canopy. Therefore, there is no need to apply a first sealing resin 18 to the outer periphery of the flexible film wiring board 11 so that it protrudes toward the ejection ports 6 to protect the outer periphery of the flexible film wiring board 11 from corrosion by the recording liquid. Therefore, the first sealing resin 18 is applied to the back surface of the flexible film wiring board 11 protruding from the support plate 9 along the outer periphery of the support plate 9. The first sealing resin 18 is also applied to the periphery of the recording element substrate 1 and part of the electrode pads 7 to protect these areas. Applying the first sealing resin 18 to part of the electrode pads 7 protects the electrical connection between the recording element substrate 1 and the flexible film wiring board 11. Here, the periphery of the recording element substrate 1 refers to the recess formed by the opening 12 in the flexible film wiring board 11, the opening in the support plate 9 similar to the opening 12, the support member 8, and the recording element substrate 1.

[0035] If a low-viscosity material is used as the first sealing resin 18, applying a predetermined amount of the first sealing resin 18 to a predetermined position will naturally spread the first sealing resin 18 due to capillary force, resulting in a good application state. For example, thermosetting epoxy resins such as CV5420FS (22 Pa·s) or CV5420AR (40 Pa·s) manufactured by Panasonic Corporation are selected as the first sealing resin 18. In particular, if CV5420AR, which has good electrical properties but high viscosity, is selected, the problem addressed by the present invention (FIGS. 13(b) and 14) is likely to occur.

[0036] Then, in order to protect the upper part of the electrical connection part between the recording element substrate 1 and the flexible film wiring board 11, that part is covered with a second sealing resin 19. Here, the upper part of the electrical connection part between the recording element substrate 1 and the flexible film wiring board 11 refers to the region from the end of the flexible film wiring board 11 to a part of the ejection port plate 5, sandwiching the lead electrodes 13 (and dummy leads 17). As the second sealing resin 19, for example, a thermosetting sealant that has extremely high mechanical strength (hardness, etc.) after curing, such as CV5420D, a thermosetting epoxy resin manufactured by Panasonic Corporation, is selected.

[0037] After the first sealing resin 18 and the second sealing resin 19 are applied, the first sealing resin 18 and the second sealing resin 19 are simultaneously heat-cured. In the above-described embodiments, the resins are cured at 100°C for 1 hour, and then at 150°C for 3 hours. The curing conditions are not particularly limited and are determined, for example, taking into consideration damage to the device due to heat.

[0038] Thereafter, a second wiring board 16 provided with external input pads 15 for applying electrical signals such as recording information from the recording apparatus main body to the liquid ejection head is electrically connected to the flexible film wiring board 11. Of course, the flexible film wiring board 11 and the second wiring board 16 may be integrally configured on the same substrate. A liquid ejection head is fabricated through the above steps. Then, the flexible film wiring board 11 is folded to fit the outer shape of a member that stores ink (recording liquid) and attached to the member, thereby fabricating a print head cartridge 100 (liquid ejection head cartridge) as shown in FIG. 11. FIG. 11 is a perspective view of the print head cartridge 100 equipped with the liquid ejection head according to the present invention.

[0039] The print head cartridge 100 is composed of a print element unit 101 (liquid ejection head), a tank holder 102, and an ink supply unit 103. The tank holder 102 detachably holds a plurality of ink tanks, each of which stores a plurality of colors of ink, such as black ink, cyan ink, magenta ink, and yellow ink. The ink supply unit 103 supplies ink from these ink tanks to the print element unit 101 (liquid ejection head). The print head cartridge 100 is detachably mounted on a carriage or the like of an inkjet printing apparatus so as to be electrically connected to the main body of the inkjet printing apparatus. The print head cartridge 100 is then used for inkjet printing on a printing medium or the like.

[0040] As described above, according to each embodiment, dummy leads are provided between adjacent groups of lead electrodes to prevent empty spaces from occurring over a desired distance in the arrangement of multiple lead electrodes provided in a device hole of a flexible film wiring substrate. One group of lead electrodes is a collection of multiple lead electrodes connected to one recording element substrate. The dummy leads are provided so as to reach the gaps between adjacent recording element substrates. This prevents the second sealing resin from being pulled and falling between the recording element substrates when the first sealing resin flows between the recording element substrates during curing. Consequently, the second sealing resin can be applied to cover the desired area in an appropriate manner (e.g., in a uniform shape), thereby providing a highly reliable liquid ejection head.

[0041] Furthermore, since the plurality of lead electrodes and the plurality of dummy leads of the flexible film wiring board can be formed in the same manufacturing process, an increase in cost can be suppressed and efficient production becomes possible.

[0042] The above-described embodiment is merely an example, and the present invention also includes configurations obtained by appropriately modifying or changing the configuration of the above-described embodiment within the scope of the gist of the present invention. The present invention also includes configurations obtained by appropriately combining the configurations of the above-described embodiment. [Explanation of symbols]

[0043] 1, 1a, 1b: recording element substrate 6: ejection port 11: flexible film wiring substrate 12: Opening 13: Lead electrode 17: Dummy lead 18: First sealing resin 19: Second sealing resin 100: Recording head cartridge 101: Recording element unit (liquid ejection head) 102: Tank holder 103: Ink supply unit

Claims

1. a flexible film wiring substrate having an opening formed therein; a plurality of ejection element substrates each having an ejection port surface provided with an ejection port for ejecting liquid, the ejection element substrates being arranged in a predetermined direction within the opening; a group of lead electrodes connected to the ejection element substrate, the lead electrodes being a collection of a plurality of lead electrodes arranged in the predetermined direction within the opening, the lead electrodes being provided on the flexible film wiring board for each of the ejection element substrates; a dummy lead provided between adjacent lead electrode groups; a first sealing resin provided around the periphery of the ejection element substrate; a second sealing resin provided above the first sealing resin so as to cover the lead electrodes and the dummy leads; and the dummy leads reach gaps between the adjacent ejection element substrates when viewed in a direction perpendicular to the ejection port surfaces of the ejection element substrates, When the distance between adjacent lead electrodes is P and the distance between the dummy lead and the lead electrode adjacent to the dummy lead is P', 0.75P≦P'≦1.25P is satisfied. A liquid ejection head characterized by:

2. a flexible film wiring substrate having an opening formed therein; a plurality of ejection element substrates each having an ejection port surface provided with an ejection port for ejecting liquid, the ejection element substrates being arranged in a predetermined direction within the opening; a group of lead electrodes connected to the ejection element substrate, the lead electrodes being a collection of a plurality of lead electrodes arranged in the predetermined direction within the opening, the lead electrodes being provided on the flexible film wiring board for each of the ejection element substrates; a dummy lead provided between adjacent lead electrode groups; a first sealing resin provided around the periphery of the ejection element substrate; a second sealing resin provided above the first sealing resin so as to cover the lead electrodes and the dummy leads; and When viewed in a direction perpendicular to the ejection port surface of the ejection element substrate, the dummy leads are reaching the gaps between the adjacent ejection element substrates, The width of the dummy lead is larger than the width of the lead electrode from the flexible film wiring board side to the gap side. A liquid ejection head characterized by:

3. a flexible film wiring substrate having an opening formed therein; a plurality of ejection element substrates each having an ejection port surface provided with an ejection port for ejecting liquid, the ejection element substrates being arranged in a predetermined direction within the opening; a group of lead electrodes connected to the ejection element substrate, the lead electrodes being a collection of a plurality of lead electrodes arranged in the predetermined direction within the opening, the lead electrodes being provided on the flexible film wiring board for each of the ejection element substrates; a dummy lead provided between adjacent lead electrode groups; a first sealing resin provided around the periphery of the ejection element substrate; a second sealing resin provided above the first sealing resin so as to cover the lead electrodes and the dummy leads; and the dummy leads reach gaps between the adjacent ejection element substrates when viewed in a direction perpendicular to the ejection port surfaces of the ejection element substrates, The dummy leads have openings formed therein that penetrate a first surface on the ejection port surface side of the ejection element substrate and a second surface that is the reverse side of the first surface. A liquid ejection head characterized by:

4. The dummy leads extend into the gap between the adjacent ejection element substrates when viewed in a direction perpendicular to the ejection port surfaces of the ejection element substrates.

4. A liquid ejection head according to claim 1.

5. The length of the dummy lead is approximately equal to the length of the lead electrode.

5. A liquid ejection head according to claim 1.

6. The dummy lead is fixed to at least one of the two ejection element substrates that form the gap.

6. A liquid ejection head according to claim 1.

7. The width of the dummy lead is greater than the width of the lead electrode.

4. The liquid ejection head according to claim 1.

8. The width of the dummy lead on the flexible film wiring board side is smaller than the width of the dummy lead on the gap side. The liquid ejection head according to claim 1 .

9. The dummy lead has a T-shape. The liquid ejection head according to claim 8 .

10. a flexible film wiring substrate having an opening formed therein; a plurality of ejection element substrates each having an ejection port surface provided with an ejection port for ejecting liquid, the ejection element substrates being arranged in a predetermined direction within the opening; a group of lead electrodes connected to the ejection element substrate, the lead electrodes being a collection of a plurality of lead electrodes arranged in the predetermined direction within the opening, the lead electrodes being provided on the flexible film wiring board for each of the ejection element substrates; a dummy lead provided between adjacent lead electrode groups; a first sealing resin provided around the periphery of the ejection element substrate; a second sealing resin provided above the first sealing resin so as to cover the lead electrodes and the dummy leads; and the dummy leads reach gaps between the adjacent ejection element substrates when viewed in a direction perpendicular to the ejection port surfaces of the ejection element substrates, The dummy lead has an L-shape. A liquid ejection head characterized by:

11. The dummy leads are provided on the flexible film wiring board. The liquid ejection head according to any one of claims 1 to 10.

12. The distance between the dummy lead and the lead electrode adjacent to the dummy lead is approximately equal to the distance between the adjacent lead electrodes. The liquid ejection head according to any one of claims 1 to 11.

13. The material of the lead electrode and the material of the dummy lead are the same. The liquid ejection head according to any one of claims 1 to 12.

14. A liquid ejection head according to any one of claims 1 to 13, a tank holder for holding a tank containing a liquid; a supply unit that supplies the liquid from the tank held by the tank holder to the liquid ejection head; A liquid ejection head cartridge having the same.

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