JP2021024216A - Liquid discharge head and manufacturing method for the same - Google Patents

Abstract

To secure flatness of a discharge port-surface of a liquid discharge head without deteriorating reliability.SOLUTION: A liquid discharge head 1 comprises a plurality of recording element substrates 10 respectively having discharge port-surfaces 30 having discharge ports for discharging liquid formed therein, and has a flat plate-like fixed member 11 having the plurality of recording element substrates 10 fixed thereto. The fixed member 11 is formed with a through hole 34 penetrated in a thickness direction which stores the plurality of recording element substrates 10. The through hole 34 has a first inner peripheral surface 35, a second inner peripheral surface 36 positioned closer to outside than the first inner peripheral surface 35, and a step surface 37 connecting the first inner peripheral surface 35 to the second inner peripheral surface 36, and perpendicular to a thickness direction of the fixed member 11. Portions of the discharge port-surfaces 30 of the plurality of recording element substrates 10 are supported on the step surface 37.SELECTED DRAWING: Figure 8

Description

The present invention relates to a liquid discharge head and a method for manufacturing the same.

Some liquid ejection heads that eject a liquid such as ink from a ejection port and record an image on a recording medium include a plurality of recording element substrates. In such a liquid discharge head, the height of the discharge port surface (the surface on which the discharge port is formed) is formed between a plurality of recording element substrates from the viewpoint of improving the accuracy of the landing position of the droplet and obtaining a high-quality image. It is preferable that there is no variation in. In Patent Document 1, a long substrate is brought close to a plurality of recording element substrates fixed on a flat stage with the discharge port surface facing downward, and a plurality of spacer members fixed to the long substrate are formed. A method of joining the recording element substrates with an adhesive is described. In this method, even if there are dimensional variations in the plurality of recording element substrates, the variations can be absorbed by the adhesive, and the flatness of the discharge port surface can be ensured.

Japanese Patent No. 4701765

In the method described in Patent Document 1, it is necessary to adjust the amount of the adhesive applied to each of the recording element substrates according to the dimensional variation of the plurality of recording element substrates. However, the adjustment is difficult, and it may not be possible to apply an appropriate amount of adhesive to the gap between the recording element substrate and the spacer member. Therefore, if the adhesive is excessively applied and protrudes from the gap, the excess adhesive may block the liquid supply port of the recording element substrate, and if the adhesive is not sufficiently applied and the gap is not completely filled, Liquid leaks may occur from that part. As a result, the liquid supply to the recording element substrate becomes unstable, and even if the flatness of the discharge port surface is ensured, a high-quality image cannot be stably obtained.
Therefore, an object of the present invention is to provide a liquid discharge head capable of ensuring the flatness of the discharge port surface without impairing reliability, and a method for manufacturing the liquid discharge head.

In order to achieve the above-mentioned object, the liquid discharge head of the present invention is a liquid discharge head including a plurality of recording element substrates, each of which has a discharge port surface on which a discharge port for discharging liquid is formed. The recording element substrate of the above has a flat plate-shaped fixing member to which the recording element substrate is fixed, and the fixing member is formed with through holes penetrating in the thickness direction to accommodate a plurality of recording element substrates, and the through holes are among the first. The peripheral surface, the second inner peripheral surface located outside the first inner peripheral surface, the first inner peripheral surface, and the second inner peripheral surface are connected and perpendicular to the thickness direction of the fixing member. The plurality of recording element substrates have a stepped surface, and a part of each discharge port surface is supported by the stepped surface.
Further, the method for manufacturing a liquid discharge head of the present invention is a method for manufacturing a liquid discharge head provided with a plurality of recording element substrates each having a discharge port surface on which a discharge port for discharging a liquid is formed, and is in the thickness direction. The first step is to prepare the fixing member, which includes a step of preparing a flat plate-shaped fixing member having a through hole formed therein and a step of accommodating a plurality of recording element substrates in the through hole of the fixing member. The inner peripheral surface of the above, the second inner peripheral surface located outside the first inner peripheral surface, the first inner peripheral surface and the second inner peripheral surface are connected, and in the thickness direction of the fixing member. The process of accommodating a plurality of recording element substrates includes forming a through hole having a vertical stepped surface in the fixing member, and includes supporting a part of each discharge port surface on the stepped surface.
According to such a liquid discharge head and its manufacturing method, even if a plurality of recording element substrates have dimensional variations only by supporting the discharge port surface of each recording element substrate with a flat stepped surface in the through hole. , The flatness of the discharge port surface of the liquid discharge head can be ensured.

According to the present invention, the flatness of the discharge port surface of the liquid discharge head can be ensured without impairing the reliability.

It is a perspective view of the liquid discharge head which concerns on 1st Embodiment. It is an exploded perspective view of the liquid discharge head which concerns on 1st Embodiment. It is a flowchart which shows the manufacturing method of 1st Embodiment. It is a perspective view which shows the manufacturing process of a discharge module. It is a top view and an exploded perspective view of a fixing member. It is an enlarged plan view and sectional view of the fixing member. It is a top view of the fixing member to which a discharge module is joined. It is an enlarged plan view and sectional view of the discharge module joined to a fixing member. It is a top view and sectional view of the recording element substrate sealed with the 2nd sealing material. It is a top view and a cross-sectional view of the fixing member which concerns on 2nd Embodiment. It is a top view of the fixing member which concerns on 3rd Embodiment. It is a top view of the fixing member which concerns on 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following embodiments do not limit the scope of the present invention. As an example, in the following embodiment, a thermal method in which bubbles are generated by an electric heat conversion element (heater) to discharge a liquid is adopted, but the present invention includes a piezo method using a piezo element and other methods. It can also be applied to a liquid discharge head that employs various liquid discharge methods. Further, the present invention can be widely applied to a liquid discharge head capable of discharging various liquids in order to perform various treatments (recording, processing, coating, irradiation, etc.) on various media. it can. The medium (including a recording medium) includes various media such as paper, plastic, film, woven fabric, metal, flexible substrate, etc., to which the liquid discharged from the liquid discharge head is applied, regardless of the material.

(First Embodiment)
The configuration of the liquid discharge head according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the liquid discharge head according to the present embodiment, and FIG. 2 is an exploded perspective view of the liquid discharge head shown in FIG.
The liquid discharge head 1 is a line-type recording head that discharges a liquid such as ink to a recording medium to be conveyed and records an image, and is linear in the longitudinal direction (direction intersecting the transfer direction of the recording medium). A plurality of recording element substrates 10 arranged in-line) are provided. The recording element substrate 10 has a discharge port surface on which a plurality of discharge ports for discharging a liquid are formed. Further, the liquid discharge head 1 has a fixing member 11 to which a plurality of recording element substrates 10 are fixed, and a plurality of flexible members each supplying an electric signal for driving an electric heat conversion element (heater) to the recording element substrate 10. It has a wiring board 12. Although the detailed configuration will be described later, the fixing member 11 has a function of supporting a plurality of discharge port surfaces of the plurality of recording element substrates 10 on the same plane. The flexible wiring board 12 is electrically connected to the recording element board 10 by, for example, a bonding wire (not shown). The electrical connection portion between the recording element substrate 10 and the flexible wiring substrate 12 is sealed with a first sealing material 41 (see FIG. 4) to protect it from external force, corrosion, and the like.

Further, the liquid discharge head 1 has a first flow path member 14 and a second flow path member 20. The first flow path member 14 is formed with a flow path that communicates with a liquid supply port (not shown) formed on a surface of the recording element substrate 10 opposite to the discharge port surface. As the material of the first flow path member 14, a material having sufficient corrosion resistance to a liquid is preferable, and for example, stainless steel, titanium, epoxy resin, alumina and the like can be used. The second flow path member 20 is formed with a common supply flow path that communicates with the flow path formed in the first flow path member 14. In addition, the second flow path member 20 is a member that bears the rigidity of the entire liquid discharge head 1. Therefore, as the material of the second flow path member 20, it is preferable that the material has sufficient corrosion resistance to the liquid as in the case of the first flow path member 14, and it is high in order to secure the rigidity of the entire liquid discharge head 1. Those having mechanical strength are preferable. Specifically, stainless steel, titanium, alumina and the like can be used as such.
The space between the plurality of recording element substrates 10 and the first flow path member 14 is sealed by the first sealing member 13, and the space between the first flow path member 14 and the second flow path member 20 is second. It is sealed by the sealing member 21. All of the sealing members 13 and 21 are crushed so as not to cause liquid leakage to the outside, and the crushing amount is set in consideration of the manufacturing tolerance and the assembly tolerance of the parts. As a method of crushing the seal members 13 and 21, for example, fastening with nuts or screws can be used. However, the present invention is not limited to this, as long as the sealing members 13 and 21 can be crushed and maintained in an appropriate amount in consideration of the manufacturing tolerance and the assembly tolerance of the parts, and other mechanical methods are used. Appropriate items such as fastening and bonding can be selected according to the application.

Next, a method of manufacturing the liquid discharge head of the present embodiment will be described with reference to the flowchart shown in FIG.

First, as shown in FIG. 4, a discharge module including the recording element substrate 10 and the flexible wiring substrate 12 is manufactured (step S1). 4 (a) to 4 (c) are perspective views showing a manufacturing process of the discharge module.
Specifically, first, the recording element substrate 10 and the flexible wiring substrate 12 are prepared. As shown in FIG. 4A, a plurality of terminals 15 are provided on the discharge port surface 30 of the recording element substrate 10, that is, the surface on which a plurality of discharge port rows each consisting of a plurality of discharge ports are formed. ing. Next, as shown in FIG. 4B, the flexible wiring board 12 is adhered to the end of the recording element substrate 10 on the side opposite to the discharge port surface on the side where the plurality of terminals 15 are provided. Join with. Then, the plurality of terminals 15 of the recording element substrate 10 and the flexible wiring board 12 are electrically connected by bonding wires (not shown). After that, as shown in FIG. 4C, the electrical connection portion between the recording element substrate 10 and the flexible wiring substrate 12 is sealed with a first sealing material 41 in order to protect it from external force, corrosion, and the like. In this way, the discharge module 16 composed of the recording element substrate 10, the flexible wiring substrate 12, and the first sealing material 41 is completed. The recording element substrate 10 and the flexible wiring board 12 may be joined by using another material having adhesiveness, or if sufficient holding force can be secured only by electrical connection. , May be omitted.

Next, as shown in FIGS. 5 and 6, a fixing member 11 to which the recording element substrate 10 is fixed is prepared (step S2). FIG. 5A is a plan view of the fixing member, and shows a surface on the side where the recording element substrate is fixed. FIG. 5B is an exploded perspective view of the fixing member shown in FIG. 5A. Is. 6 (a) is an enlarged plan view showing a part of the fixing member shown in FIG. 5 (a), and FIG. 6 (b) is a cross section taken along the line AA of FIG. 6 (a). It is a figure.
The fixing member 11 is a flat plate-shaped member having a through hole 34 penetrating in the thickness direction, and is a thin plate member (first plate member) 31, a thick plate member (second plate member) 32, and a nut. It has an insertion member 33. These are laminated to each other, and at least a part thereof is directly bonded to each other by, for example, thermocompression bonding or welding. The through hole 34 of the fixing member 11 includes a first inner peripheral surface 35 formed in the thin plate member 31, a second inner peripheral surface 36 formed in the thick plate member 32, and a first inner peripheral surface 35. It has a stepped surface 37 that connects to the second inner peripheral surface 36. The stepped surface 37 is composed of a surface to which the thick plate member 32 of the thin plate member 31 is joined, and is a surface perpendicular to the thickness direction of the fixing member 11. As will be described later, the plurality of recording element substrates 10 are accommodated and fixed in the through holes 34 of the fixing member 11.

The fixing member 11 is fastened to the second flow path member 20 that supports the entire liquid discharge head 1 by a nut (not shown) inserted into the nut insertion member 33. Therefore, the fixing member 11 needs to have rigidity that can withstand fastening, and such rigidity is ensured by the above-mentioned direct joining. In the case of joining with an adhesive (adhesive joining), deterioration of the joined portion over time and deterioration due to environmental influences such as temperature and humidity may occur, but direct joining can suppress such problems. , The joint strength and rigidity can be improved as compared with the adhesive joint. In particular, in the case of the line type head as in the present embodiment, the size of the through hole 34 formed in the thin plate member 31 and the thick plate member 32 becomes large, and it becomes more difficult to secure the rigidity. Sufficient rigidity can be ensured by direct joining. In the present embodiment, the fixing member 11 is composed of three members 31 to 33, but as long as the function required for the fixing member 11 is exhibited, the number of plate members constituting the fixing member 11 is limited. Absent. Therefore, the fixing member 11 may be an integral member similarly formed by, for example, machining or double-sided etching.
It is preferable that the material of the fixing member 11 has sufficient corrosion resistance against liquid and high mechanical strength, and has a small difference in linear expansion coefficient from silicon which is a base material of the recording element substrate 10. As such a material, for example, stainless steel, titanium, silicon carbide, alumina and the like can be used. Among them, it is preferable to use stainless steel such as SUS304 or SUS430, and in particular, SUS430 having a small coefficient of linear expansion is preferably used because the distribution amount is relatively large and the manufacturing cost can be suppressed.

Next, as shown in FIGS. 7 and 8, a plurality of discharge modules 16 are joined to the fixing member 11 (step S3). 7 (a) and 7 (b) are plan views of the fixing members to which the discharge modules are joined, and FIG. 7 (a) is a view seen from the side opposite to the discharge port surface of the recording element substrate. Yes, FIG. 7B is a view seen from the side of the discharge port surface. 8 (a) is an enlarged plan view of a part of the discharge module shown in FIG. 7 (a), and FIG. 8 (b) is a further enlarged view of the discharge module, FIG. 8 (c). Is a cross-sectional view taken along the line BB of FIG. 8 (b).
Specifically, first, the fixing member 11 is fixed to a jig having a high flatness by a fastening means such as a screw. As a result, even if the fixing member 11 is warped or twisted, it can be corrected and the flatness of the stepped surface 37 of the fixing member 11 can be further improved. Then, a plurality of discharge modules 16 are housed in the through holes 34 so that the discharge port surface 30 of the recording element substrate 10 and the stepped surface 37 of the through hole 34 face each other, and the peripheral edge portion of the discharge port surface 30 is accommodated by, for example, an adhesive. Is joined to the stepped surface 37. In this way, the peripheral edge of the discharge port surface 30 of the recording element substrate 10 is supported by the stepped surface 37 having a high flatness, and as a result, the height of the discharge port surface 30 (the position of the fixing member 11 in the thickness direction) becomes substantially constant. It can be aligned and the flatness of the discharge port surface 30 can be ensured. The stepped surface 37 may support a part of the discharge port surface 30 of the recording element substrate 10. A configuration in which the stepped surface 37 supports the peripheral edge of the discharge port surface 30 as in the present embodiment is preferable in that the recording element substrate 10 can be stably supported.

The first sealing material 41 arranged from the discharge port surface 30 to the side surface of the recording element substrate 10 is prevented from coming into contact with the fixing member 11 by the relief portion 50 formed in the through hole 34. That is, in the through hole 34, at a position facing the first sealing material 41 when the discharge module 16 is housed in the through hole 34, a relief portion 50 extended to the outside of the other portion is formed. Has been done. Therefore, the recording element substrate 10 is supported by the stepped surface 37 only by the discharge port surface 30, and is not supported by the fixing member 11 by the first sealing material 41 which may cause variation in shape. It is possible to prevent variations in the height of the discharge port surface 30.
The thickness of the thin plate member 31 is preferably as thin as possible, and is preferably 80 μm or less, for example. As a result, the distance between the discharge port surface 30 supported by the thin plate member 31 and the recording medium can be shortened, and the accuracy of the landing position of the droplet including the influence of the air flow between the discharge port and the recording medium is deteriorated. Can be reduced. In addition, since the rise of the first inner peripheral surface 35 from the discharge port surface 30 is also low, it becomes difficult for liquid to collect between the discharge port surface 30 and the first inner peripheral surface 35, thereby suppressing poor recovery. It is also possible to suppress scraping of the recovery member. However, with respect to the thickness of the thin plate member 31, an appropriate thickness can be selected within an acceptable range for the performance of the liquid discharge head.

Next, as shown in FIG. 9, the gap around the recording element substrate 10, specifically, the gap between the adjacent recording element substrates 10 and the gap between the recording element substrate 10 and the through hole 34 is secondly sealed. Seal with the stopper 40 (step S4). 9 (a) is a plan view of the recording element substrate sealed with the second sealing material, and FIG. 9 (b) is a cross-sectional view taken along the line CC of FIG. 9 (a). is there.
By sealing the periphery of the recording element substrate 10 with the second sealing material 40, the holding force thereof can be improved as compared with the case where the recording element substrate 10 is fixed only with the adhesive. In addition, the second encapsulant 40 can protect the side surface and the end portion of the recording element substrate 10, such as intrusion of liquid into the gap around the recording element substrate 10 and formation of an excess liquid pool portion. Problems can be suppressed. It is preferable that the second sealing material 40 is filled up to the gap in the relief portion 50. As a result, it is possible to prevent the liquid from flowing from the discharge port surface 30 side of the recording element substrate 10 to the back surface side of the recording element substrate 10 through the relief portion 50, and to prevent the liquid from staying in the relief portion 50.

If the second sealing material 40 flows out from the relief portion 50 and rides on the first sealing material 41, the protruding height from the discharge port surface 30 becomes high, and the sealing materials 40 and 41 are recorded. May interfere with the medium. In order to avoid this, it is necessary to increase the distance to the recording medium, but as a result, the distance between the discharge port surface 30 and the recording medium becomes long, so that the image quality due to the deviation of the landing position of the droplets There is concern that the price will decline. Further, when the second sealing material 40 that has flowed out reaches the discharge port surface 30, it may block the discharge port and cause a discharge failure. From such a viewpoint, it is preferable that the distance between the first inner peripheral surface 35 and the first sealing material 41 in the relief portion 50 is as narrow as possible. As a result, a meniscus is likely to be formed between the first inner peripheral surface 35 and the first sealing material 41, and it is possible to prevent the second sealing material 40 from flowing out from the relief portion 50.
As the material of the second sealing material 40, a material having a relatively low curing temperature, for example, curing at room temperature or curing at a temperature of up to about 100 ° C. is preferable. The elastic modulus of the second encapsulant 40 after curing is preferably lower than the elastic modulus of the adhesive that joins the recording element substrate 10 to the fixing member 11 after curing, and is, for example, 50 MPa or less. Is preferable. Due to the thermal history in the assembly process, temperature changes during use, etc., misalignment due to the difference in linear expansion coefficient between the fixing member 11 and the recording element substrate 10 and cracking of the recording element substrate 10 may occur. Such a defect can be suppressed by lowering the elastic modulus of the second sealing material 40.

Finally, the fixing member 11, the sealing members 13, 21 and the flow path members 14, 20 are assembled by, for example, screws or adhesives to complete the liquid discharge head 1 (step S5).

In the present embodiment, by arranging a plurality of recording element substrates 10 having parallelograms in a straight line, the length of the liquid discharge head 1 in the transport direction of the recording medium is suppressed from increasing, and the recording element substrate is suppressed. It is possible to suppress black streaks and white spots at the joints between the ten. However, the arrangement of the recording element substrate 10 is not limited to this, and an appropriate arrangement can be selected according to the requirements required for the liquid discharge head 1. For example, it is possible to arrange the recording element substrates in a staggered pattern, or to arrange rectangular recording element substrates diagonally so that the discharge ports at the ends of the recording element substrates overlap. Further, the planar shape of the recording element substrate 10 is not limited to the parallelogram as in the present embodiment, and may be, for example, a rectangle, a trapezoid, or another shape.

(Second Embodiment)
The configuration of the liquid discharge head according to the second embodiment of the present invention will be described with reference to FIG. 10 (a) is a plan view of the recording element substrate joined to the fixing member of the present embodiment, and FIG. 10 (b) is a cross-sectional view taken along the line DD of FIG. 10 (a). .. FIG. 10 (c) is a cross-sectional view of a recording element substrate sealed with a second sealing material, and is a diagram corresponding to FIG. 10 (b).
In the present embodiment, as shown in FIG. 10 (b), the side surface (first sealing) of the recording element substrate 10 as the second inner peripheral surface 36 of the relief portion 50 toward the first inner peripheral surface 35. It is inclined so that the distance from the surface on which the material 41 is arranged) becomes narrow. As a result, the filling amount of the second sealing material 40 can be reduced, and the capillary force generated in the gap between the side surface of the recording element substrate 10 and the second inner peripheral surface 36 is utilized to utilize the capillary force of the second sealing material 40. Can be quickly filled, the tact time of the sealing process can be shortened, and productivity can be improved. The inclined shape may be such that the second inner peripheral surface 36 of the relief portion 50 is inclined as a whole, and may be, for example, a flat shape, a stepped shape, or a curved surface shape. Other configurations are the same as in the first embodiment.

(Third Embodiment)
The configuration of the liquid discharge head according to the third embodiment of the present invention will be described with reference to FIG. 11 (a) and 11 (b) are plan views of a recording element substrate joined to the fixing member of the present embodiment, and FIG. 11 (a) shows a flexible wiring board for easy viewing. It has been omitted.
In the present embodiment, the second inner peripheral surface 36 of the relief portion 50 is inclined as shown in the second embodiment, and the recording element substrate 10 is directed from both ends in the circumferential direction toward the central portion. It is inclined so that the distance from the side surface of the As a result, a stronger capillary force can be generated, and the second sealing material 40 can be filled more quickly, so that the productivity can be further improved.

(Fourth Embodiment)
The configuration of the liquid discharge head according to the fourth embodiment of the present invention will be described with reference to FIG. 12 (a) and 12 (b) are plan views of a recording element substrate joined to the fixing member of the present embodiment, and FIG. 12 (a) shows a flexible wiring board for easy viewing. It has been omitted.
In the present embodiment, the second inner peripheral surface 36 of the relief portion 50 is inclined as shown in the second embodiment, and the recording element substrate is directed from one end to the other end in the circumferential direction. It is inclined so that the distance from the side surface of 10 becomes narrow. As a result, as in the third embodiment, the second encapsulant 40 can be quickly filled by utilizing the stronger capillary force, and the width of the flexible wiring board 12 varies and the recording element substrate 10 and the like. It is possible to deal with variations in the pasting position and the like.

1 Liquid discharge head 10 Recording element substrate 11 Fixing member 34 Through hole 37 Step surface

Claims (14)

A liquid discharge head provided with a plurality of recording element substrates each having a discharge port surface on which a discharge port for discharging a liquid is formed.
It has a flat plate-shaped fixing member to which the plurality of recording element substrates are fixed, and has
The fixing member is formed with through holes that penetrate in the thickness direction and accommodate the plurality of recording element substrates.
The through hole includes a first inner peripheral surface, a second inner peripheral surface located outside the first inner peripheral surface, the first inner peripheral surface, and the second inner peripheral surface. Has a stepped surface perpendicular to the thickness direction of the fixing member.
The plurality of recording element substrates are liquid discharge heads in which a part of each discharge port surface is supported by the stepped surface. The liquid discharge head according to claim 1, wherein the peripheral edge portion of each discharge port surface is supported by the stepped surface. A first unit that is arranged on the side surface of the recording element substrate, a wiring board that is electrically connected to the recording element substrate, and the electrical connection portion between the recording element substrate and the wiring board. Each has a plurality of discharge modules, each of which has a sealing material of
The liquid discharge according to claim 1 or 2, wherein the through hole has a relief portion extended outward so as not to come into contact with the first sealing material at a position facing the first sealing material. head. In the plurality of recording element substrates, a part of each discharge port surface is bonded to the stepped surface with an adhesive.
The liquid discharge head according to claim 3, further comprising a second sealing material for sealing the gap between the adjacent recording element substrates and the gap between the plurality of recording element substrates and the through holes. The liquid according to claim 4, wherein the second inner peripheral surface of the relief portion is inclined so that the distance from the side surface of the recording element substrate becomes narrower toward the first inner peripheral surface. Discharge head. The distance between the second inner peripheral surface of the relief portion and the side surface of the recording element substrate increases from both ends in the circumferential direction toward the center, or from one end to the other end in the circumferential direction. The liquid discharge head according to claim 4 or 5, which is inclined so as to be narrowed. The liquid discharge head according to any one of claims 4 to 6, wherein the second sealing material has an elastic modulus lower than that of the adhesive. The liquid discharge head according to any one of claims 1 to 7, wherein the fixing member is made of stainless steel. The liquid discharge head according to claim 8, wherein the stainless steel is SUS430. The fixing member is directly joined to the first plate member having the first inner peripheral surface, and at least a part thereof is directly joined to the first plate member, and the second plate member has the second inner peripheral surface. The liquid discharge head according to any one of claims 1 to 9, which has the above. The liquid discharge head according to claim 10, wherein the first plate member has a thickness smaller than the thickness of the second plate member. The liquid discharge head according to claim 11, wherein the thickness of the first plate member is 80 μm or less. The liquid discharge head according to any one of claims 1 to 12, wherein the plurality of recording element substrates are linearly arranged along the longitudinal direction of the liquid discharge head. A method for manufacturing a liquid discharge head having a plurality of recording element substrates each having a discharge port surface on which a discharge port for discharging a liquid is formed.
The process of preparing a flat plate-shaped fixing member having through holes that penetrate in the thickness direction, and
A step of accommodating the plurality of recording element substrates in the through hole of the fixing member is included.
The steps of preparing the fixing member include a first inner peripheral surface, a second inner peripheral surface located outside the first inner peripheral surface, the first inner peripheral surface, and the second inner peripheral surface. It includes forming the through hole in the fixing member which is connected to the inner peripheral surface and has a stepped surface perpendicular to the thickness direction of the fixing member.
A method for manufacturing a liquid discharge head, wherein the step of accommodating the plurality of recording element substrates includes supporting a part of each discharge port surface on the stepped surface.

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