Liquid ejection head and manufacturing method thereof

Abstract

To enhance the reliability of a liquid discharge head by suppressing an unneeded influx of an adhesive.SOLUTION: A liquid discharge head 1 has a recording element substrate 3, which discharges a liquid, and a support member 2, which has a recess 21 for storing the recording element substrate 3 with a channel 22 formed to supply the liquid to the recording element substrate 3, where the recording element substrate 3 is joined by means of an adhesive 26 with the bottom face 24 of the recess 21 to which the channel 22 opens. In the bottom face 24 of the recess 21, a groove part 23 adjacent to a junction region 25 with which the recording element substrate 3 is joined to make the width wider as it leaves the junction region 25 is formed, and a part adjacent to the junction region 25 of the groove part 23 is filled with the adhesive 26.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] A liquid ejection head used in an inkjet recording device or the like is known that includes a recording element substrate that ejects liquid and a support member having a recess that accommodates the recording element substrate. A liquid flow path for supplying liquid to the recording element substrate is formed in the support member, and the recording element substrate is bonded with an adhesive to the bottom surface of the recess in which the liquid flow path opens. When the recording element substrate is bonded, the adhesive pressed against the recording element substrate is pushed not only outward but also inward, and if it flows into the liquid flow path or the liquid supply path of the recording element substrate that communicates with the liquid flow path, it may cause liquid ejection failure. Patent Document 1 describes a technology that prevents the adhesive from flowing into the liquid flow path or liquid supply path by inclining the area of ​​the bottom surface of the recess where the adhesive is applied from the inside to the outside in the depth direction and forcibly pushing the adhesive pressed against the recording element substrate outward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-36837 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are many constraints to apply the adhesive well to the inclined surface. For example, it is necessary to prevent the adhesive from flowing down the inclined surface, and to do so, it is necessary to use an adhesive with high thixotropy or to add a structure to the inclined surface to stop the flow of the adhesive. In addition, the transfer method cannot be used to apply the adhesive to the inclined surface, and even if a coating method is used, it is difficult to apply the adhesive well to the inclined surface depending on the size of the coating needle. SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENTS Accordingly, an object of the present invention is to provide a highly reliable liquid ejection head and a method for manufacturing the same, which are capable of suppressing unwanted flow of adhesive. [Means for solving the problem]

[0005] In order to achieve the above object, a liquid ejection head of the present invention comprises a recording element substrate that ejects liquid, and a support member having a recess that houses the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded to a bottom surface of the recess in which the flow path opens, with an adhesive. In one embodiment, a groove portion is formed in the bottom surface of the recess adjacent to a bonding area where the recording element substrate is bonded and which increases in width as it moves away from the bonding area, and an adhesive is filled in a portion of the groove portion adjacent to the bonding area. In another embodiment, a groove portion is formed in the bottom surface of the recess adjacent to the opening of the flow path. death A groove is formed whose width increases with increasing distance from the opening, and the portion of the groove adjacent to the opening is filled with adhesive. A method for manufacturing a liquid ejection head according to the present invention includes a recording element substrate that ejects liquid, and a support member having a recess that accommodates the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded to a bottom surface of the recess in which the flow path opens with an adhesive. In one aspect, the method includes a step of forming a groove portion on the bottom surface of the recess that is adjacent to a bonding area to which the recording element substrate is bonded and that increases in width with increasing distance from the bonding area, and a step of applying adhesive to the bonding area and then bonding the recording element substrate to the bonding area. In the step of bonding the recording element substrate, the adhesive is pressed by the recording element substrate to flow into the groove portion and is filled in a portion of the groove portion adjacent to the bonding area. In another aspect, the bottom surface of the recess is provided with Flow path The method includes a step of forming a groove portion that increases in width as it approaches the opening and moves away from the opening, and a step of applying adhesive along the peripheral edge of the opening and then bonding a recording element substrate to the peripheral edge of the opening. In the step of bonding the recording element substrate, the adhesive is pressed against the recording element substrate and flows into the groove portion, filling the portion of the groove portion that is adjacent to the opening. Effect of the Invention

[0006] According to the present invention, it is possible to suppress unnecessary flow of adhesive and improve the reliability of the liquid ejection head. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of a liquid ejection head according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded plan view of a liquid ejection head according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view of a recording element substrate according to an embodiment of the present invention. [Figure 4] 4A and 4B are a plan view and a cross-sectional view of a recess in a support member according to one embodiment of the present invention. [Diagram 5] 4A to 4C are plan views showing each stage of a bonding process according to one embodiment of the present invention. [Figure 6] 3A to 3C are cross-sectional views showing each stage of a bonding process according to one embodiment of the present invention. [Figure 7] FIG. 13 is a plan view showing a modified example of a groove according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] Fig. 1(a) is a perspective view showing a liquid ejection head according to an embodiment of the present invention, and Fig. 1(b) is an exploded perspective view of the liquid ejection head shown in Fig. 1(a) Fig. 2 is an exploded plan view of the liquid ejection head of this embodiment. The liquid ejection head 1 ejects liquid (for example, ink of three colors, cyan, magenta, and yellow) to record an image on a recording medium, and includes a support member 2, a recording element substrate 3, and an electric wiring substrate 4. The support member 2 is formed by resin molding, and in this embodiment, a resin material containing 35% glass filler to improve rigidity is used. The support member 2 includes a recess 21 that accommodates the recording element substrate 3, and a liquid flow path 22 for supplying liquid to the recording element substrate 3. An absorbent that holds liquid is accommodated inside the support member 2, and the liquid ejected from the liquid ejection head 1 is stored therein. The support member 2 also includes a groove portion 23 that is formed on the bottom surface of the recess portion 21 at the same time as the support member 2 is molded. The detailed configuration and function of the groove portion 23 will be described later.

[0010] The recording element substrate 3 has a plurality of ejection ports 31 for ejecting liquid, and is bonded with an adhesive to the bottom surface of the recess 21 on the surface opposite to the surface on which the ejection ports 31 are formed (hereinafter referred to as the "front surface") on the surface opposite to the surface on which the ejection ports 31 are formed (hereinafter referred to as the "back surface"). The gap between the recording element substrate 3 and the support member 2 is sealed with a first sealing material 5 made of, for example, a thermosetting resin. The electric wiring board 4 is joined to the support member 2 at a position where the recording element board 3 is inserted into a device hole 41 formed in the electric wiring board 4. The electric wiring board 4 is electrically connected to two end faces of the recording element board 2 via electrode terminals 42 in order to supply the recording element board 3 with electric signals and power for ejecting liquid, and the electrical connection is sealed with a second sealing material 6 made of, for example, a thermosetting resin. The electric wiring board 4 is provided with an external signal input terminal 43 for receiving a control signal from a device body such as an inkjet recording device, and the external signal input terminal 43 is connected to the electrode terminal 42 by copper foil wiring.

[0011] Figure 3 is a plan view of the recording element substrate of this embodiment, where Figure 3(a) shows the front surface on which the ejection ports are formed, and Figure 3(b) shows the back surface opposite the side on which the ejection ports are formed. The recording element substrate 3 has a silicon substrate having a thickness of, for example, 0.62 mm, and an ejection port forming member provided on one surface of the silicon substrate. A plurality of ejection ports 31 are formed in the ejection port forming member, and a plurality of supply paths 32 are formed in the silicon substrate, which communicate with the plurality of ejection ports 31 and open to the rear surface of the recording element substrate 3. The plurality of ejection ports 31 form a plurality of ejection port rows (six in the illustrated example), and the supply path 32 is provided for every two ejection port rows. A plurality of energy generating elements (not shown) that generate energy used to eject liquid, and wiring (not shown) for supplying power to each energy generating element are formed on one surface of the silicon substrate. In addition, a connection terminal 33 that is connected to an electrode terminal 42 of the electric wiring substrate 4 is formed on an end portion in the longitudinal direction of the recording element substrate 3.

[0012] Fig. 4(a) is a plan view showing a recess of the support member of the present embodiment, and is an enlarged view of the area surrounded by the dotted line in Fig. 2. Fig. 4(b) is a cross-sectional view taken along line AA in Fig. 4(a). As described above, the support member 2 has a groove 23 formed on the bottom surface 24 of the recess 21. The groove 23 is provided at a position on the bottom surface 24 of the recess 21 adjacent to the bonding area 25 to which the recording element substrate 3 is bonded, and is formed so as to increase in width as it moves away from the bonding area 25. Specifically, the groove 23 is formed close to both ends in the longitudinal direction of the rectangular opening 22a of the liquid flow path 22 that opens into the bonding area 25, and is formed so as to increase in width as it moves away from the opening 22a along the longitudinal direction of the opening 22a. Although details will be described later, the groove 23 guides the adhesive applied to the bonding area 25 and pressed against the recording element substrate 3 when the recording element substrate 3 is bonded to the bottom surface 24 of the recess 21 to the outside, thereby preventing the adhesive from flowing into the liquid flow path 22 or the supply path 32.

[0013] In the following, the bonding process of bonding the recording element substrate to the support member in the manufacturing method of the liquid ejection head of this embodiment will be described. Figures 5(a) and 6(a) are plan views showing each stage of the bonding process of this embodiment, and both correspond to Figure 4(a). Figures 5(b) and 6(b) are cross-sectional views showing each stage of the bonding process of this embodiment, and both correspond to Figure 4(b). 5(a) and 5(b), adhesive 26 is applied by coating or transfer to a bonding area 25 of the bottom surface 24 of the recess 21 where the recording element substrate 3 is bonded, specifically, along the periphery of the opening 22a of the liquid flow path 22. The adhesive 26 is preferably one that has liquid resistance such as ink resistance, and for example, a thermosetting adhesive containing epoxy resin as the main component is used, but other adhesives may be used as long as the performance such as liquid resistance and adhesiveness meets the requirements for the liquid ejection head 1. Next, the recording element substrate 3 is bonded to the bonding area 25 to which the adhesive 26 has been applied. At this time, when the adhesive 26 pressed against the recording element substrate 3 is spread and contacts the groove portion 23, a meniscus force is generated at this time, and a force pulling the adhesive 26 outward from the bonding area 25 along the groove portion 23 acts on the adhesive 26. As a result, as shown in FIG. 6(a) and FIG. 6(b), the adhesive 26 flows into the groove portion 23 and fills the portion of the groove portion 23 adjacent to the bonding area 25. In this way, the recording element substrate 3 and the support member 2 are bonded in a state in which the adhesive 26 pressed against the recording element substrate 3 is prevented from being pushed inward toward the opening portion 22a of the liquid flow path 22.

[0014] After that, the electric wiring board 4 is joined to the support member 2, and the connection terminals 33 of the recording element board 3 are connected to the electrode terminals 42 of the electric wiring board 4, thereby electrically connecting the recording element board 3 and the electric wiring board 4. Then, the gap between the recording element board 3 and the support member 2 is sealed with the first sealant 5, and the electrical connection portion between the recording element board 3 and the electric wiring board 4 is sealed with the second sealant 6. The first sealant 5 is injected into the gap between the side of the recording element board 3 on which the connection terminals 33 are not provided and the side of the recess 21 facing the side, and flows into the gap below the connection terminals 33 by capillary action to fill it. After the gap between the recording element board 3 and the support member 2 is entirely filled with the first sealant 5, the second sealant 6 is applied from above the electrode terminals 42 so as to cover them.

[0015] In this manner, in this embodiment, when the adhesive 26 applied to the bonding area 25 is pressed against the recording element substrate 3, it comes into contact with the groove 23, and the meniscus force generated at that time can guide the adhesive 26 along the groove 23 to the outside of the bonding area 25. This prevents the adhesive 26 from being pushed inward toward the opening 22a of the liquid flow path 22, and as a result, it is possible to prevent the adhesive 26 from flowing into the liquid flow path 22 and the supply path 32 of the recording element substrate 3 that communicates with the liquid flow path 22. In addition, the groove 23 becomes wider as it moves away from the bonding area 25, i.e., the opening 22a of the liquid flow path 22, so that the meniscus force acting on the adhesive 26 weakens as it moves away from the bonding area 25, i.e., the opening 22a of the liquid flow path 22. Therefore, the filling of the adhesive 26 into the groove 23 can be stopped at an appropriate position, and the state of the adhesive 26 applied between the recording element substrate 3 and the support member 2 can be maintained in a good condition. Furthermore, in this embodiment, since the bonding area 25 to which the adhesive 26 is applied is a flat area, the adhesive 26 can be applied with high precision.

[0016] 7(a) to 7(c) are enlarged plan views showing modified examples of the support member of this embodiment. In the above-described embodiment, the groove 23 has a linear side surface in a plan view, but the shape of the groove 23 is not limited to this as long as a meniscus force acts on the adhesive 26 in contact with the groove 23. For example, as shown in FIG. 7(a), the groove 23 may have a curved side surface in a plan view. In the above-described embodiment, the groove 23 extends in the longitudinal direction of the opening 22a of the liquid flow path 22 on the center line along the longitudinal direction of the opening 22a, but the position of the groove 23 is not limited to this. For example, as shown in FIG. 7(b), the groove 23 may extend parallel to the longitudinal direction of the opening 22a at a position shifted from the center line along the longitudinal direction of the opening 22a. Specifically, the groove 23 may be formed adjacent to a position where the adhesive 26 applied in a linear or strip shape intersects, that is, a position where the adhesive 26 pressed against the recording element substrate 3 is likely to spread. In the above-described embodiment, the groove 23 is separated from the opening 22a of the liquid flow path 22, but as shown in Fig. 7(c), it may be connected to the opening 22a of the liquid flow path 22. In this case, the adhesive 26 applied to the bonding region 25 flows into the communication portion between the groove 23 and the opening 22a due to the pressing force when bonding the recording element substrate 3, thereby isolating the groove 23 from the liquid flow path 22. Thereafter, the adhesive 26 is pulled outward along the groove 23 by the meniscus force acting on the adhesive 26, and is filled in the portion of the groove 23 adjacent to the bonding region 25, as in the above-described embodiment. [Explanation of symbols]

[0017] 1 Liquid ejection head 2 Supporting member 3. Recording element board 21 Recess 23 Groove 26 Adhesive

Claims

1. A liquid ejection head comprising: a recording element substrate that ejects liquid; and a support member having a recess that houses the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded with an adhesive to a bottom surface of the recess in which the flow path opens, a groove portion is formed on the bottom surface of the recess portion, the groove portion being adjacent to a bonding area to which the recording element substrate is bonded and having a width increasing with distance from the bonding area; A liquid ejection head, wherein the adhesive is filled in a portion of the groove adjacent to the joining region.

2. A liquid ejection head comprising: a recording element substrate that ejects liquid; and a support member having a recess that houses the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded with an adhesive to a bottom surface of the recess in which the flow path opens, a groove portion that increases in width as it approaches an opening of the flow channel and moves away from the opening is formed on the bottom surface of the recess; A liquid ejection head, wherein the adhesive is filled in a portion of the groove adjacent to the opening.

3. The liquid ejection head according to claim 1 , wherein the bonding area is formed flat.

4. 4. The liquid ejection head according to claim 1, wherein the flow path has a rectangular opening in the joining region, and the groove is formed adjacent to an end of the opening in a longitudinal direction.

5. The liquid ejection head according to claim 2 , wherein a peripheral portion of the bottom surface of the recess around the opening is formed flat.

6. 6. The liquid ejection head according to claim 2, wherein the opening is rectangular, and the groove is formed adjacent to an end of the opening in a longitudinal direction.

7. The liquid ejection head according to claim 4 , wherein the groove portion is formed so that its width increases with increasing distance from the opening portion along the longitudinal direction of the opening portion.

8. The liquid ejection head according to claim 7 , wherein the groove portion extends in the longitudinal direction on a center line along the longitudinal direction of the opening portion.

9. The liquid ejection head according to claim 8 , wherein the groove portion communicates with the opening portion.

10. The liquid ejection head according to claim 7 , wherein the groove portion extends parallel to the longitudinal direction of the opening portion at a position offset from a center line along the longitudinal direction of the opening portion.

11. The liquid ejection head according to claim 1 , wherein the groove has a straight or curved side surface in a plan view.

12. A method for manufacturing a liquid ejection head, comprising: a recording element substrate that ejects liquid; and a support member having a recess that houses the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded with an adhesive to a bottom surface of the recess in which the flow path opens, the method comprising: forming a groove portion on the bottom surface of the recess portion, the groove portion being adjacent to a bonding area to which the recording element substrate is bonded and having a width increasing with distance from the bonding area; and after applying the adhesive to the bonding area, bonding the recording element substrate to the bonding area, A method for manufacturing a liquid ejection head, wherein in the step of bonding the recording element substrate, the adhesive is pressed against the recording element substrate, flows into the groove portion, and fills a portion of the groove portion adjacent to the bonding area.

13. A method for manufacturing a liquid ejection head, comprising: a recording element substrate that ejects liquid; and a support member having a recess that houses the recording element substrate and in which a flow path for supplying liquid to the recording element substrate is formed, the recording element substrate being bonded with an adhesive to a bottom surface of the recess in which the flow path opens, the method comprising: forming a groove portion on the bottom surface of the recess, the width of which increases with increasing distance from the opening of the flow channel toward the opening; and after applying the adhesive along the periphery of the opening, bonding the recording element substrate to the periphery of the opening, A method for manufacturing a liquid ejection head, wherein in the step of bonding the recording element substrate, the adhesive is pressed against the recording element substrate, flows into the groove portion, and fills a portion of the groove portion adjacent to the opening portion.

14. The method for manufacturing a liquid ejection head according to claim 12 or 13, wherein the groove portion is formed simultaneously with molding of the support member.

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