Liquid ejection head

Abstract

To provide a liquid discharge head capable of securing strength of a substrate, while preventing liquid consumption amounts from deviating between liquid supply ports.SOLUTION: A liquid discharge head comprises: a discharge port forming member 4 forming discharge ports 5 for discharging liquid; a substrate 1 having a plurality of liquid supply ports 7 for supplying liquid to the discharge ports 5 and partition walls 19 formed between the plurality of liquid supply ports; and a support member 18 for supporting the substrate 1. In a view from a position opposite to a main surface 20 of the substrate 1, the liquid supply port 7 extends in a longitudinal direction of the substrate 1, and the plurality of liquid supply ports 7 are arrayed in a shorter direction of the substrate 1. At least a part of the partition walls 19 are non-abutting portions 19a not abutting on the support member 18. In a view from a position opposite to the main surface 20 of the substrate 1, also an opening width at any place of the liquid supply port 7 is equal to or smaller than an opening width on a side of the liquid supply port 7.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] An example of a liquid ejection device (recording device) that performs recording by ejecting liquid onto a recording medium such as paper is an inkjet printer. An inkjet printer includes a liquid ejection head that ejects liquid (ink). A liquid ejection head generally includes a recording element substrate having an ejection port forming member in which a plurality of ejection ports for ejecting liquid are formed, and a substrate in which a liquid supply port for supplying liquid to the ejection ports is formed.

[0003] Patent Document 1 discloses a recording element substrate in which a plurality of liquid supply ports are individually and independently formed on the substrate, as shown in Fig. 8. Fig. 8(a) is a plan view of the substrate as viewed from a position facing the main surface 20 of the substrate 1, and Fig. 8(b) is a cross-sectional view of the AA' cross section shown in Fig. 8(a). Liquid is supplied to the ejection port 5 from an ink tank that contains the liquid (ink) via the liquid supply port 7. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-269016 A Summary of the Invention [Problem to be solved by the invention]

[0005] Depending on the recording pattern (printing pattern), a large amount of liquid may be ejected from a particular ejection port. In this case, if a configuration is adopted in which multiple liquid supply ports are formed independently of one another as shown in FIG. 8, more liquid will be consumed from the liquid supply port that communicates with that particular ejection port. This causes the liquid in the ink tank connected to that liquid supply port to run out of ink earlier than other ink tanks. Therefore, even if the other ink tanks are sufficiently filled with liquid, liquid cannot be ejected from the particular ejection port, and it may be necessary to replace the liquid ejection head itself with a new one.

[0006] Therefore, a configuration in which a plurality of liquid supply ports 7 are connected to each other as shown in FIG. 9 is conceivable. FIG. 9(a) is a plan view corresponding to FIG. 8(a), and FIG. 9(b) is a cross-sectional view of the AA' section shown in FIG. 9(a). As shown in FIG. 9(b), a plurality of liquid supply ports 7 are connected to each other. This communication between the liquid supply ports occurs in the longitudinal direction (Y direction) of the substrate 1. By connecting a plurality of liquid supply ports 7 to each other, even if the consumption of liquid from a specific ejection port is intense, liquid can be supplied from other liquid supply ports 7. This makes it possible to avoid a case in which the consumption of liquid is intense only in a specific ink tank. However, in the configuration shown in FIG. 9, in order to connect a plurality of liquid supply ports 7 to each other, the partition wall 19 formed between the liquid supply ports is removed by etching or the like, and the strength of the substrate 1 is reduced. If the strength of the substrate 1 is reduced, a crack (crack) 12 may occur in the substrate 1 when an external force 13 or the like is applied to the substrate 1.

[0007] In view of the above, an object of the present invention is to provide a liquid ejection head capable of suppressing unevenness in the amount of liquid consumed between liquid supply ports while ensuring the strength of the substrate. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a liquid ejection head including a substrate having an ejection port forming member that forms an ejection port for ejecting liquid, a plurality of liquid supply ports for supplying liquid to the ejection ports of the ejection port forming member, and partition walls formed between the plurality of liquid supply ports, and a support member that supports the substrate, wherein, when viewed from a position facing a main surface of the substrate, the liquid supply ports extend along the longitudinal direction of the substrate, and when viewed from a position facing the main surface of the substrate, the plurality of liquid supply ports are arranged along the lateral direction of the substrate, at least a portion of the partition walls is a non-abutting portion that does not abut against the support member, adjacent liquid supply ports among the plurality of liquid supply ports are in communication with each other through a gap between the non-abutting portion and the support member, and when a cross section of the liquid supply port in the lateral direction is viewed, an opening width at any point of the liquid supply port is equal to or smaller than an opening width of the liquid supply port on the support member side. Further, the partition wall further has a contact portion that contacts the support member, and among the liquid supply ports extending along the longitudinal direction, when the opening width at the center in the substrate thickness direction of the portion adjacent to the contact portion in the short hand direction is a, and the opening width at the center in the substrate thickness direction of the portion adjacent to the non-contact portion in the short hand direction is b, a < b is satisfied. It is characterized by: Effect of the Invention

[0009] SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENTS The present invention has an object to provide a liquid ejection head capable of ensuring the strength of a substrate while suppressing unevenness in the amount of liquid consumed between liquid supply ports. [Brief description of the drawings]

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

[0011] Hereinafter, an embodiment of the present invention will be described in detail.

[0012] (First embodiment) A first embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a perspective view showing a liquid ejection head 16 of this embodiment. As shown in Fig. 1, the liquid ejection head 16 is mainly composed of a recording element substrate 15 having ejection ports 5 (Fig. 2) for ejecting liquid, a flexible wiring substrate 17, and a housing 18 that contains ink to be supplied to the ejection ports 5. The flexible wiring substrate 17 has wiring for supplying power to the recording element substrate 15. The housing 18 also serves as a member for supporting the recording element substrate 15, and may be referred to as a supporting member in the following description.

[0013] FIG. 2 is a perspective view showing a recording element substrate 15. The recording element substrate 15 has energy generating elements 14 formed at a predetermined pitch to generate energy for discharging liquid from the discharge ports 5. The substrate 1 has a plurality of liquid supply ports 7 formed for supplying liquid from a housing 18 to the discharge ports 5. The substrate 1 is made of, for example, silicon. In particular, a single crystal silicon substrate is preferable. Discharge ports 5 corresponding to the energy generating elements 14 are formed on the substrate 1 by a discharge port forming member 4. The discharge port forming member 4 is preferably one that is required to have high mechanical strength as a structural material, adhesion to a base, ink resistance, and resolution for patterning a fine pattern as the discharge port 5. Examples of materials that satisfy these characteristics include cationic polymerization type epoxy resin compositions. Examples of epoxy resins include a reaction product of bisphenol A and epichlorohydrin, and a reaction product of bromobisphenol A and epichlorohydrin. Examples of other examples include a reaction product of phenol novolac or o-cresol novolac and epichlorohydrin. The epoxy resin preferably has an epoxy equivalent of 2000 or less, and more preferably has an epoxy equivalent of 1000 or less.

[0014] Examples of photo-cationic polymerization initiators for curing epoxy resins include compounds that generate acid upon irradiation with light. Examples of such initiators include aromatic sulfonium salts and aromatic iodonium salts. If necessary, a wavelength sensitizer may be added. Examples of such wavelength sensitizers include SP-100, which is commercially available from ADEKA Corporation.

[0015] The ejection port forming member 4 can be made of, for example, a silicon substrate, a metal layer, or an inorganic film such as SiN, other than the resin.

[0016] FIG. 3(a) is a plan view of the recording element substrate 15 seen from the substrate 1 side. FIG. 3(b) is a cross-sectional view of the AA' cross section shown in FIG. 3(a). As shown in FIG. 3(a), a plurality of liquid supply ports are arranged along the short-side direction (X direction) of the substrate 1, and partition walls 19 are formed between the liquid supply ports. The partition walls 19 are part of the substrate. In the cross section shown in FIG. 3(b), a part of the partition wall 19 is removed, so that the liquid supply ports communicate with each other. That is, when viewed from a position facing the main surface 20 of the substrate 1, the liquid supply port 7 extends in the longitudinal direction (Y direction) of the substrate 1, and at least a part of the partition wall 19 is a non-contact part 19a that is a part that does not contact the support member 18. FIG. 3 shows an example in which the entire partition wall 19 is a non-contact part 19a. Therefore, in FIG. 3, this communication between the liquid supply ports occurs over the longitudinal direction (Y direction) of the substrate 1.

[0017] A gap 2 is generated between the non-contact portion 19a of the partition wall 19 and the support member 18. Since the gap 2 allows liquid to flow, even if a large amount of liquid is discharged from an ejection port communicating with the liquid supply port 7 located at the left end shown in FIG. 3, the liquid in the liquid supply port 7 located at the center or right end flows into the liquid supply port 7 at the left end. As a result, even if a large amount of liquid is consumed only from a specific ejection port, ink is supplied from other liquid supply ports, so that it is possible to suppress the early difficulty in supplying liquid only to a specific ejection port. Then, as shown in FIG. 3(b), when a cross section of the liquid supply port 7 in the short direction (X direction) is viewed, the opening width d at any point of the liquid supply port 7 is equal to or smaller than the opening width (d1 or smaller) of the liquid supply port 7 on the support member side. Since the liquid supply port 7 has a shape that satisfies such conditions, it is possible to obtain a substrate 1 with a larger portion remaining than the substrate 1 shown in FIG. 9 of the comparative example, and the rigidity of the substrate 1 can be ensured. Therefore, it is possible to suppress deformation of the recording element substrate 15.

[0018] Next, a method for manufacturing the recording element substrate 15 of this embodiment will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing each step of the method for manufacturing the recording element substrate 15, and shows the AA' cross section shown in FIG. 3 in each step. First, as shown in FIG. 4(a), a substrate 1 was prepared as a single crystal substrate of silicon, on whose front surface an adhesion improving layer 3 and a flow path forming member 10 were formed, and on the rear surface a mask layer 9 of polyetheramide resin was formed. In this case, the dimensions of the opening of the liquid supply port 7 of the mask layer 9 were set to 750 um in the short side direction (X direction) of the substrate 1 and 9000 um in the long side direction (Y direction). The long side dimension of the non-contact portion was set to 400 um, and the long side dimension of the contact portion was set to 600 um. As for the non-contact portion that communicates adjacent liquid supply ports in the short side direction, as shown in FIG. 4(a), the mask layer 9 is not formed between adjacent liquid supply ports.

[0019] 4(b), a discharge port forming member 4 was formed on the flow path forming member 10 using a cationic polymerization type epoxy resin. After that, in order to form a liquid supply port, a blind hole 11 was formed in the substrate 1 using a laser beam of a triple harmonic of a YAG laser (THG: wavelength 355 nm).

[0020] Next, as shown in FIG. 4(c), anisotropic etching is performed from the back surface of the substrate 1. The etching solution used for the anisotropic etching is TMAH (tetramethylammonium hydroxide), and the etching is performed at a liquid temperature of 80° C. and an etching time of 8.5 hours. This etching forms liquid supply ports 7 that communicate with each other. As the etching solution enters the inside of the non-through holes 11 formed on the back surface of the substrate 1 and etching progresses, openings where the etching mask layer 9 is not formed and parts of the partition walls of the adjacent liquid supply ports 7 are etched. As etching progresses on the substrate surface, the liquid supply ports 7 also expand laterally to form the desired openings.

[0021] 4(d), the mask layer 9 on the back surface of the substrate 1 and the flow path forming member 10 on the front surface of the substrate 1 were removed. Finally, the substrate 1 was cut and separated by dicing or the like to form the recording element substrate 15, and the liquid ejection head 16 was completed by connecting electrical wiring and bonding the recording element substrate 15 to a support member 18.

[0022] Second embodiment The second embodiment will be described with reference to FIG. 5. The same reference numerals are used for the same parts as those in the first embodiment, and the description will be omitted. FIG. 5 shows a recording element substrate 15 in this embodiment. FIG. 5(a) is a plan view of the substrate 1 as seen from the rear surface side. FIG. 5(b) is a cross-sectional view of the AA' section shown in FIG. 5(a). FIG. 5(c) is a cross-sectional view of the BB' section shown in FIG. 5(a). In this embodiment, as shown in FIG. 5, the partition wall 19 has a non-contact portion 19a that does not contact the support member 18, and a contact portion 19b that contacts the support member 18. That is, in this embodiment, only a part of the partition wall 19 is the non-contact portion 19a.

[0023] Since the partition 19 has the abutment portion 19b that abuts against the support member 18, the support member 18 and the substrate 1 are bonded by an adhesive at the abutment portion 19b, and the strength of the substrate 1 can be ensured. This makes it possible to suppress deformation of the recording element substrate 15. Furthermore, since the abutment portion 19b is formed, more of the substrate 1 can be left, and the rigidity of the substrate 1 can be maintained. Therefore, according to this embodiment, the liquid flows through the gap 2 between the non-abutment portion 19a and the support member 18, which suppresses unevenness in the amount of liquid consumed between the liquid supply ports, while ensuring the strength of the substrate.

[0024] Also, in the short side direction (X direction) of the substrate 1, let the opening width at the center in the substrate thickness direction of the liquid supply port 7 formed at a position adjacent to the non-contact portion 19a be b. And let the opening width at the center in the substrate thickness direction of the liquid supply port 7 formed at a position adjacent to the contact portion 19b be a. In this case, it is preferable to form the liquid supply port 7 so that the relationship a < b holds. Since the gap 2 between the non-contact portion 19a and the support member 18 is a minute space, the fluid resistance is greater than that of the liquid supply port 7. Therefore, it may be difficult to smoothly supply liquid from other liquid supply ports to the liquid supply port 7 where the liquid consumption is large. Thus, as shown in FIGS. 5(b) and (c), for the liquid supply ports in the portion adjacent to the gap 2, it is preferable to form them so as to satisfy the above-described relationship a < b. Thereby, the liquid can flow more smoothly between the liquid supply ports.

[0025] (Third Embodiment) The third embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a schematic view showing the recording element substrate 15 in the present embodiment, and FIG. 6(a) is a plan view corresponding to FIG. 3(a). FIG. 6(b) is a cross-sectional view taken along the A - A' cross-section shown in FIG. 6(a). FIG. 6(c) is a cross-sectional view taken along the B - B' cross-section shown in FIG. 6(a). In the present embodiment, the contact portion 19b of the partition wall 19 is formed at the center portion having the lowest rigidity in the longitudinal direction (Y direction) of the substrate 1. Thereby, the strength of the substrate 1 can be more ensured. Here, the central portion of the partition wall 19 refers to the region surrounded by a circle with a radius of d / 5 (d is the total length in the longitudinal direction of the partition wall 19) centered on the center of gravity in the longitudinal direction (Y direction) of the partition wall 19. Also, in the present embodiment as in the second embodiment, it is more preferable that the opening width of the liquid supply port satisfies the relationship a < b.

[0026] FIG. 7 shows a modified example of the recording element substrate 15 in this embodiment, and FIG. 7(a) is a plan view corresponding to FIG. 6(a). FIG. 7(b) is a cross-sectional view taken along the line AA' in FIG. 7(a). FIG. 7(c) is a cross-sectional view taken along the line BB' in FIG. 7(a). The recording element substrate 15 shown in FIG. 7 is different from the recording element substrate 15 shown in FIG. 6 in that the abutting portion 19b of the partition wall 19 is not only provided in the center in the longitudinal direction (Y direction) but is also formed at the end. Here, the end of the partition wall 19 refers to a region from the end of the partition wall 19 in the longitudinal direction (Y direction) to d / 5 (d is the total length of the partition wall 19 in the longitudinal direction).

[0027] From the viewpoint of increasing the strength of the partition wall 19, the abutting portion 19b is preferably formed in a central portion in the longitudinal direction of the partition wall 19. By forming the abutting portion 19b not only in the central portion but also at the end portions in the longitudinal direction of the partition wall 19, the strength of the partition wall 19 can be further ensured.

[0028] In the second and third embodiments, the non-contact portions 19a are arranged in a line in the short-side direction (X direction) of the substrate 1 when viewed from a position facing the main surface 20 of the substrate 1, but the second and third embodiments are not limited to this. That is, the non-contact portions 19a and the contact portions 19b may be arranged in a line in the short-side direction. Furthermore, the non-contact portions 19a and the contact portions 19b may be arranged in a staggered manner when viewed from a position facing the main surface 20 of the substrate 1. By arranging them in a staggered manner, the rigidity of the recording element substrate 15 is kept uniform regardless of the location. As a result, there are fewer locations with locally low rigidity, so that, for example, even if a force is applied to the recording element substrate 15 from any direction, the recording element substrate 15 can be prevented from being deformed. [Explanation of symbols]

[0029] 1 Board 2. Gap 4. Discharge port forming member 5 Outlet 7 Liquid supply port 18 Support member 19 Bulkhead 19a Non-contact part 20 Main surface of the substrate

Claims

1. a discharge port forming member that forms a discharge port for discharging liquid; a substrate having a plurality of liquid supply ports for supplying liquid to the ejection ports of the ejection port forming member, and partition walls formed between the plurality of liquid supply ports; A support member for supporting the substrate; In a liquid ejection head comprising: When viewed from a position facing a main surface of the substrate, the liquid supply port extends along a longitudinal direction of the substrate, When viewed from a position facing a main surface of the substrate, the plurality of liquid supply ports are arranged along a short-side direction of the substrate, At least a portion of the partition wall is a non-contact portion that does not contact the support member, the liquid supply ports that are adjacent to each other among the plurality of liquid supply ports communicate with each other through a gap between the non-contact portion and the support member, when a cross section of the liquid supply port in the short side direction is viewed, an opening width at any point of the liquid supply port is equal to or smaller than an opening width of the liquid supply port on a side of the support member, The partition wall further has an abutment portion that abuts against the support member, A liquid ejection head characterized in that, of the liquid supply ports extending along the longitudinal direction, when the opening width at the center in the thickness direction of the substrate of the portion adjacent to the abutting portion in the short direction is a and the opening width at the center in the thickness direction of the substrate of the portion adjacent to the non-abutting portion in the short direction is b, the relationship a<b is satisfied.

2. The liquid ejection head according to claim 1 , wherein the contact portion is joined to the support member by an adhesive.

3. 2. The liquid ejection head according to claim 1, wherein the partition wall is entirely the non-contact portion.

4. 2. The liquid ejection head according to claim 1, wherein only a portion of the partition wall is the non-contact portion.

5. 5. The liquid ejection head according to claim 1, wherein the non-contact portion is formed in a plurality of portions aligned in the short side direction when viewed from a position facing the main surface of the substrate.

6. A discharge port forming member that forms a discharge port for discharging a liquid; a substrate having a plurality of liquid supply ports for supplying liquid to the ejection ports of the ejection port forming member, and partition walls formed between the plurality of liquid supply ports; A support member for supporting the substrate; In a liquid ejection head comprising: When viewed from a position facing a main surface of the substrate, the liquid supply port extends along a longitudinal direction of the substrate, When viewed from a position facing a main surface of the substrate, the plurality of liquid supply ports are arranged along a short-side direction of the substrate, At least a portion of the partition wall is a non-contact portion that does not contact the support member, the liquid supply ports that are adjacent to each other among the plurality of liquid supply ports communicate with each other through a gap between the non-contact portion and the support member, when a cross section of the liquid supply port in the short side direction is viewed, an opening width at any point of the liquid supply port is equal to or smaller than an opening width of the liquid supply port on a side of the support member, The partition wall further has an abutment portion that abuts against the support member, The liquid ejection head according to claim 1, wherein the non-contact portion and the contact portion are formed side by side in the short side direction when viewed from a position facing the main surface of the substrate.

7. A discharge port forming member that forms a discharge port for discharging a liquid; a substrate having a plurality of liquid supply ports for supplying liquid to the ejection ports of the ejection port forming member, and partition walls formed between the plurality of liquid supply ports; A support member for supporting the substrate; In a liquid ejection head comprising: When viewed from a position facing a main surface of the substrate, the liquid supply port extends along a longitudinal direction of the substrate, When viewed from a position facing a main surface of the substrate, the plurality of liquid supply ports are arranged along a short-side direction of the substrate, At least a portion of the partition wall is a non-contact portion that does not contact the support member, the liquid supply ports that are adjacent to each other among the plurality of liquid supply ports communicate with each other through a gap between the non-contact portion and the support member, when a cross section of the liquid supply port in the short side direction is viewed, an opening width at any point of the liquid supply port is equal to or smaller than an opening width of the liquid supply port on a side of the support member, The partition wall further has an abutment portion that abuts against the support member, A liquid ejection head, characterized in that the contact portions are formed in a staggered pattern when viewed from a position facing the main surface of the substrate.

8. 8. The liquid ejection head according to claim 1, wherein the substrate is a silicon substrate.

Images