JP2023127146A - liquid discharge head - Google Patents

Abstract

To provide a liquid discharge head which can inhibit expansion of voids.SOLUTION: A liquid discharge head 21 includes: a first substrate 1 having a first surface 23; and a second substrate 17 having a second surface 24. The first substrate 1 and the second substrate 17 are joined through an adhesive. The first surface 23 is formed with a first protruding part 7 protruding to the second surface 24, and the second surface 24 is formed with a second protruding part 8 protruding to the first surface 23.SELECTED DRAWING: Figure 2

Description

The present invention relates to a liquid ejection head made up of a plurality of substrates.

2. Description of the Related Art A printing apparatus that performs printing by ejecting liquid onto a recording medium such as paper has a liquid ejection head that includes an ejection port that ejects liquid and a pressure generating element that generates pressure for ejection. A liquid ejection head is sometimes formed by bonding a plurality of substrates together using an adhesive. A typical example is a piezo head method that drives a piezoelectric element to eject liquid.

When bonding multiple substrates with adhesive, it is important that there are no cavities (areas where no adhesive is applied, hereinafter referred to as voids) in the adhesive layer formed between the substrates. . If there is a void in the adhesive layer, if the void expands due to various factors such as thermal contraction of the adhesive itself or a pressure difference between the inside and outside of the substrate, it can become a space through which liquid can pass. That is, a liquid flow path is formed in a region where an adhesive should originally be formed. The area in which the adhesive is formed in the liquid ejection head is an area necessary for separating channels through which liquids (inks) of different colors flow. Therefore, if liquid flows through this area, there will be functional or quality problems.

Patent Document 1 discloses a method of suppressing the expansion of voids by forming convex portions on a substrate. As the voids in the adhesive layer expand, the voids collide with the convex portions and further expansion of the voids is inhibited. In other words, the expansion of the void can be stopped by the convex portion.

Japanese Patent Application Publication No. 2015-182441

In the method of Patent Document 1, a convex portion is formed only on one of the substrates to be bonded. Therefore, if voids occur on the side of the substrate where the convex portions are not formed, there is a risk that the voids will expand. This will be explained in detail using FIG. FIG. 1 is a schematic diagram showing how a first substrate 1 on which a convex portion 7 is formed and a second substrate 17 on which a convex portion is not formed are bonded together with an adhesive 3. As shown in FIG. As shown in FIG. 1(a), voids 2 are generated on the second substrate 17 side where no convex portions are formed. When the void 2 expands in this state, since there is no obstacle in the direction of movement of the void 2 to block its progress, the void 2 expands into the flow path 4 as shown in FIGS. 1(b) and (c). It expands, and the flow path 4 and the void 2 end up communicating with each other. An arrow 13 indicates the direction in which the void expands. As a result, the liquid flowing through the flow path 4 flows into the enlarged void 5, resulting in functional or quality problems.

In view of the above problems, an object of the present invention is to provide a liquid ejection head that can further suppress the expansion of voids.

In order to solve the above problems, the present invention includes a first substrate having a first surface and a second substrate having a second surface opposite to the first surface, In the liquid ejection head in which the first substrate and the second substrate are bonded to each other via an adhesive between the first surface and the second surface, the first surface has the second substrate. A first protrusion protruding toward the surface is formed, and a second protrusion protruding toward the first surface is formed on the second surface. do.

According to the present invention, it is possible to provide a liquid ejection head that can further suppress the expansion of voids.

A schematic diagram showing a conventional example. FIG. 1 is a schematic diagram showing a liquid ejection head according to a first embodiment. FIG. 1 is a schematic diagram showing a liquid ejection head according to a first embodiment. FIG. 1 is a schematic diagram showing a liquid ejection head according to a first embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a second embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a third embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a fourth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a fifth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a sixth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a seventh embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to an eighth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a ninth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a tenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to an eleventh embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a twelfth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a thirteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a fourteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a fifteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a sixteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a seventeenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to an eighteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a nineteenth embodiment. FIG. 7 is a schematic diagram showing a liquid ejection head according to a twentieth embodiment. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion. FIG. 3 is a schematic diagram showing a method for manufacturing a convex portion.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings. In addition, in each figure, the same reference number is attached|subjected about the same member, and the overlapping description is abbreviate|omitted.

(First embodiment)
The liquid ejection head of this embodiment is installed in an inkjet printer (not shown). There are various types of inkjet printers, but printers are generally equipped with a carriage (not shown) that can move in the scanning direction, and the carriage is equipped with a liquid ejection head that ejects ink onto the print medium. It is being Ink passes through a liquid flow path from an ink tank and is ejected onto a printing target from an ejection port provided in a liquid ejection head. A desired pattern is printed by repeating carriage scanning and ejection.

FIG. 2 is a schematic diagram showing a liquid ejection head 21 of this embodiment formed by bonding a plurality of substrates including piezoelectric elements 19 with an adhesive. FIG. 2A is a perspective view of the liquid ejection head 21. FIG. FIG. 2(b) is a sectional view taken along line U-U' shown in FIG. 2(a). FIG. 2(c) is an enlarged view of the area surrounded by the broken line shown in FIG. 2(b). The liquid ejection head 21 includes a first substrate 1, a second substrate 17, and a third substrate 22. A channel 4 through which a liquid flows is formed in the first substrate 1 . A piezoelectric element 19 and a flow path 4 are formed on the second substrate 17 . A discharge port 18 is formed in the third substrate 22 for discharging liquid onto an object such as paper. The first substrate 1, the second substrate 17, and the third substrate 22 are each bonded via an adhesive 3. Adhesive 3 is applied between a first surface 23 of first substrate 1 and a second surface 24 opposite to first surface 23 . As shown in FIG. 2(c), a convex portion 7 (also referred to as a first convex portion 7) is formed on the first substrate 1, and a second convex portion 8 is formed on the second substrate 17. . The first protrusion 7 protrudes toward the second surface 24 , and the second protrusion 8 protrudes toward the first surface 23 .

FIG. 3 is a schematic diagram illustrating the effects of this embodiment using the cross-sectional view shown in FIG. 2(c). It shows the process in which void 2 expands. A void 2 is present in a part of the layer of adhesive 3 between the first substrate 1 and the second substrate 17 . The void 2 expands in accordance with the arrow 13 due to various factors such as contraction due to heating to harden the adhesive 3 and pressure difference between the left and right spaces (FIG. 3(a)). When the void 2 collides with the second convex portion 8, the advancing direction of the void 2 changes from the left direction in the drawing to the downward direction in the drawing (FIG. 3(b)). Thereafter, when the void 2 reaches the surface of the first substrate 1, it moves leftward again (FIG. 3(c)). However, the hardening of the adhesive 3 progresses until then, and the hardening of the adhesive 3 is completed before the void 2 advances to the channel 4.

Therefore, in this embodiment, by providing a convex portion on each of the two substrates to be joined, the distance over which the void 2 can travel is increased. Thereby, expansion of the void 2 can be further suppressed. Furthermore, since the convex portions are formed on each of the two substrates, even if the void 2 is generated on either the first substrate side or the second substrate side, the void 2 is formed on the first convex portion 7 or the second substrate side. The void 2 will always collide with one of the convex portions 8. Therefore, expansion of the void 2 can be further suppressed. When the void 2 expands, the liquid in the flow path 4 may adhere to the piezoelectric element 19, which may cause the piezoelectric element 19 to malfunction. According to this embodiment, failure of the piezoelectric element 19 and the like can also be suppressed.

FIG. 4A is a top view of the first substrate 1 around the first convex portion 7. FIG. FIG. 4(b) is a cross-sectional view taken along line AA′ shown in FIG. 4(a). FIG. 4 shows the adhesive 3 omitted. Further, for explanation, the second convex portion 8 is also illustrated. The heights of the first convex portion 7 and the second convex portion 8 are approximately the same. The first convex part 7 and the second convex part 8 may be on the inside (flow path 4 side) or the outside, but the place where voids 2 are likely to occur is between the first convex part 7 and the second convex part 8 It is necessary to form it in a position where it will not come. In addition, in order to obtain a greater effect, it is preferable that a portion of the first convex portion 7 and the second convex portion 8 overlap by a certain amount or more in the vertical direction. It is preferable that the total height of the second convex portions 8 is greater than or equal to the height (thickness) of the adhesive layer. As shown in FIG. 4(a), the first convex portion 7 and the second convex portion 8 continuously surround the opening of the flow path 4. As shown in FIG. Thereby, no matter where the void 2 occurs, it is possible to prevent the void 2 from expanding to the flow path.

(Second embodiment)
A second embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 5(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 5(b) is a diagram of this embodiment corresponding to FIG. 4(b). This embodiment is characterized in that the side surfaces of the first convex portion 7 and the second convex portion 8 are curved. Thereby, the surface area of the first convex portion 7 and the second convex portion 8 can be increased, and the distance over which the void 2 travels can be further secured. Therefore, expansion of the void 2 can be further suppressed.

(Third embodiment)
A third embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 6(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 6(b) is a diagram of this embodiment corresponding to FIG. 4(b). Unlike the first embodiment, the heights of the first convex portion 7 and the second convex portion 8 are different. Either the first protrusion 7 or the second protrusion 8 may be higher or lower, but the effect of the present invention can be further enhanced by providing the higher protrusion near the location where the void 2 is likely to occur. I can do it. Also, in the third embodiment, in order to obtain a greater effect, it is preferable that a portion of the first convex portion 7 and the second convex portion 8 overlap by a certain amount or more in the vertical direction; It is preferable that the total height of the first convex portion 7 and the second convex portion 8 is greater than or equal to the height of the adhesive layer.

(Fourth embodiment)
A fourth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 7(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 7(b) is a diagram of this embodiment corresponding to FIG. 4(b). In the fourth embodiment, the side surfaces of the first convex portion 7 and the second convex portion 8 have an uneven shape. Thereby, the surface area of the convex portion can be further increased, and the distance over which the void 2 travels can be further secured. Therefore, expansion of the void 2 can be further suppressed.

(Fifth embodiment)
A fifth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 8(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 8(b) is a diagram of this embodiment corresponding to FIG. 4(b). The fifth embodiment is characterized in that the cross-sectional shapes of the first convex portion 7 and the second convex portion 8 are trapezoidal. By making the cross-sectional shapes of the first convex portion 7 and the second convex portion 8 trapezoidal, the surface area can be increased compared to a rectangular cross-section. Thereby, the surface area of the convex portion can be further increased, and the distance over which the void 2 travels can be further secured. Therefore, expansion of the void 2 can be further suppressed.

(Sixth embodiment)
A sixth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 9(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 9(b) is a diagram of this embodiment corresponding to FIG. 4(b). In the sixth embodiment, the first convex portion 7 and the second convex portion 8 have a triangular cross-sectional shape. Since the cross-sectional shapes of the first protrusion 7 and the second protrusion 8 are triangular, the volume of the protrusion itself can be made smaller, so the volume of the adhesive 3 can be reduced. It is possible to reduce concerns about adhesion caused by

(Seventh embodiment)
A seventh embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 10(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 9(b) is a diagram of this embodiment corresponding to FIG. 4(b).

In the seventh embodiment, two first protrusions 7 are arranged on the first substrate 1 side, and one second protrusion 8 is arranged on the second substrate 17 side. In this way, even if the number of first protrusions 7 and second protrusions 8 is not the same, a pair of protrusions can be formed by having one or more protrusions on each joint surface. . By providing more convex portions, the effects of the present invention can be further enhanced.

(Eighth embodiment)
An eighth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 11(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 11(b) is a diagram of this embodiment corresponding to FIG. 4(b). In the eighth embodiment, two first protrusions 7 are arranged on the first substrate 1 side, and two second protrusions 8 are arranged on the second substrate 17 side. That is, a plurality of first protrusions 7 and second protrusions 17 are formed. Although the effects of the present invention can be further enhanced by providing more protrusions in the path, it is important to provide an appropriate number depending on the length of the installation area and the width of the protrusions. Regarding the positions at which the two sets of protrusions are arranged, it is preferable to arrange the respective protrusions apart from each other in order to more reliably obtain the effects of the present invention with respect to the void 2. For this reason, it is preferable to arrange the adhesive closer to the inner side and the outer side of the area where the adhesive is applied.

(Ninth embodiment)
A ninth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 12(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 12(b) is a diagram of this embodiment corresponding to FIG. 4(b). A configuration is shown in which 16 first protrusions 7 are arranged on the first substrate 1 side, and 12 second protrusions 8 are arranged on the second substrate 17 side. The convex portion exists so as to surround the flow path 4. In this way, by forming the first convex portion 7 and the second convex portion 8 in block shapes separated from each other, a sufficient volume of the adhesive 3 can be ensured and adhesiveness can be maintained. That is, the first protrusion 7 and the second protrusion 8 intermittently surround the opening of the flow path 4.

(Tenth embodiment)
A tenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 13(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 13(b) is a diagram of this embodiment corresponding to FIG. 4(b). The thirteenth embodiment is characterized in that the lengths of the first convex portion 7 and the second convex portion 8 are changed depending on the direction and position. As a result, if the void is likely to expand in the horizontal direction of the drawing, it is possible to suppress the expansion in the horizontal direction, and to ensure a bonding area in the vertical direction since the area in which the convex portion is formed is small. That is, it is possible to both suppress the expansion of voids and ensure adhesive strength.

(Eleventh embodiment)
An eleventh embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 14(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 14(b) is a diagram of this embodiment corresponding to FIG. 4(b). In the diagonal direction, the distance from the flow path 4 to the end is long, and in the vertical and horizontal directions it is shorter than in the diagonal direction. Therefore, there is a high possibility that the voids will expand in the vertical and horizontal directions and reach the flow path 4. In such a case, the protrusions in the diagonal direction may not be provided, and the protrusions may be provided only in the vertical and horizontal directions. By providing convex portions in the necessary locations and only in the necessary regions, it is possible to both ensure adhesive strength and suppress the expansion of voids.

(12th embodiment)
A twelfth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 15(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 15(b) is a diagram of this embodiment corresponding to FIG. 4(b). A feature of this embodiment is that the first substrate 1 is formed with an escape groove 14 for the adhesive 3 in addition to the first convex portion 7 . The escape groove 14 is for storing excess adhesive in the recess and suppressing the adhesive from protruding from the substrate. Thereby, it is possible to suppress not only the expansion of voids but also the extrusion of the adhesive.

Since the relief groove 14 may become a place where voids occur, when forming the relief groove 14, the first convex portion 7 and the second convex portion 8 are formed along the direction in which the relief groove 14 is formed. It is preferable. Thereby, expansion of voids caused by the escape groove 14 can be suitably suppressed. In FIG. 15, the relief groove 14 is formed on the first substrate 1, but the relief groove 14 may be formed on the second substrate 17. That is, it is sufficient that the escape groove 14 is formed in at least one of the first substrate 1 and the second substrate 17.

(13th embodiment)
A thirteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 16 is a schematic diagram illustrating the effects of this embodiment. FIG. 16(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIGS. 16(b) to 16(d) are diagrams of this embodiment corresponding to FIG. 4(b). Note that the recess 9 is not shown in FIG. 16(a). It shows the process in which void 2 expands. A void 2 exists in a part of the layer of adhesive 3 between the first substrate 1 and the second substrate 17 (FIG. 16(b)). The void 2 expands according to the arrow 13 due to various factors such as contraction due to heating to harden the adhesive 3 and pressure difference between the left and right spaces (FIG. 16(c)). When the void 2 collides with the first convex portion 7, the advancing direction of the void 2 changes from the left direction in the drawing to the upward direction in the drawing (FIG. 16(d)). A recess 9 is present in the bonding surface of the second substrate 17 . The first convex portion 7 and the concave portion 9 are not in contact with each other. As shown in FIG. 16(d), when the void 2 reaches around the bottom of the recess 9, it moves leftward again. However, the hardening of the adhesive 3 progresses until then, and the hardening of the adhesive 3 is completed before the void 2 advances to the channel 4.

Therefore, in this embodiment, the distance that the void 2 travels is increased by combining the convex portion and the concave portion. Thereby, expansion of the void 2 can be further suppressed. In addition, by inserting a part of the first protrusion 7 into the recess 9, even if the void 2 is generated on either the first substrate side or the second substrate side, the first protrusion 7 Void 2 will definitely collide. Therefore, expansion of the void 2 can be further suppressed.

The convex portion may be an existing convex portion such as a wiring pattern. The width of the concave portion 9 is wider than the width of the convex portion, and by joining, it is necessary that a part of the convex portion overlaps the concave portion 9 by a certain amount or more. Furthermore, in order to obtain a sufficient effect of the invention with the convex-concave structure, it is desirable to arrange it on the side close to the flow path 4 or on the opposite side close to the end of the area where bonding is performed. The figure shows, as an example, a convex-concave structure provided on the side closer to the flow path 4. Since the cross-sectional shapes of both the first protrusion 7 and the recess 9 are rectangular, it is relatively easy to actually form the protrusion and the recess 9.

In FIG. 16, the convex portion 7 is provided on the first substrate 1 and the concave portion 9 is provided on the second substrate 17, but the present embodiment may be reversed. That is, the first substrate 1 may be provided with the recessed portion 9 and the second substrate 17 may be provided with the convex portion.

(Fourteenth embodiment)
A fourteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 17(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 17(b) is a diagram of this embodiment corresponding to FIG. 4(b). Note that the recess 9 is not shown in FIG. 17(a). The cross-sectional shape of the first convex portion 7 is trapezoidal, and the cross-sectional shape of the recessed portion 9 provided in the second substrate 17 is trapezoidal. The width of the concave portion 9 is wider than the width of the convex portion, and by joining, it is necessary that a part of the convex portion overlaps the concave portion 9 by a certain amount or more. Furthermore, in order to obtain a sufficient effect of the invention with the convex-concave structure, it is desirable to arrange it on the side close to the flow path 4 or on the opposite side close to the end of the area where bonding is performed. Since the cross-sectional shapes of both the first convex part 7 and the concave part 9 are trapezoidal, the surface area can be further increased, so the path for the voids to communicate becomes longer, making it difficult to form the communicating voids 5. I can do it.

(15th embodiment)
A fifteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 18(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 18(b) is a diagram of this embodiment corresponding to FIG. 4(b). Note that the recess 9 is not shown in FIG. 18(a). The figure shows a state in which two sets of convex-concave structures are provided, in which the first convex portion 7 provided on the first substrate 1 has a rectangular cross-sectional shape, and the concave portion 9 provided on the second substrate 17 has a rectangular cross-sectional shape. There is. When two or more sets of convex-concave structures are provided, in order to obtain a sufficient effect of the invention, it is desirable to arrange them on the side closer to the flow path 4 and the side closer to the end of the bonding area, respectively. By providing two or more sets of convex-concave structures, the effect of suppressing the occurrence of communication voids 5 can be increased.

(16th embodiment)
A sixteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 19(a) is a diagram of this embodiment corresponding to FIG. 4(a). FIG. 19(b) is a diagram of this embodiment corresponding to FIG. 4(b). The adhesive 3 on the left side is high and the adhesive 3' on the right side is low. If the film thickness difference of the adhesive 3 is non-uniform within the plane as described above, a low place can become the starting point 2 of a communicating void. In this case, as shown in FIGS. 15(a) and 15(b), the present invention can be implemented only at a location close to the starting point 2 of the communicating void. By providing the convex portions in the necessary locations and only in the necessary areas, the present invention can be implemented without worrying about adhesion.

(17th embodiment)
A seventeenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. 20(a) is a top view of the wafer state before cutting into individual elements, (b) is a cross-sectional view of the wafer, and (c) is an enlarged cross-sectional view of a part of the chip near the center of the wafer. (d) is an enlarged cross-sectional view of a part of the chip near the outer periphery of the wafer. This embodiment is one form of a convex-convex portion, and shows how the present invention is applied only to chips near the outer periphery of the wafer. As shown in FIG. 20(b), a curved second substrate 17 may be bonded to a flat first substrate 1. At this time, since there is a high possibility that a gap will be formed between the adhesive 3 and the second substrate 17 in the wafer outer chip 15, a starting point 2 of a communicating void may occur in the wafer outer chip 15. In such a case, it is also possible to choose to provide a convex-convex portion on the wafer outer chip 15 and not provide any convex portion on the wafer center chip as before. In this way, by providing the convex portions only in the necessary areas at the necessary locations, the effects of the present invention can be obtained without causing concerns about adhesion in other areas.

(18th embodiment)
An eighteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. 21(a) is a top view of the wafer state before cutting into individual elements, (b) is a cross-sectional view of the wafer, (c) is an enlarged cross-sectional view of a part of the chip near the center of the wafer, and (d) ) is an enlarged cross-sectional view of a part of the chip near the outer periphery of the wafer. This embodiment is one form of a convex-convex portion, and shows how the present invention is applied only to chips near the center of the wafer. As shown in FIG. 20(b), a downwardly curved second substrate 17 may be bonded to a flat first substrate 1. At this time, there is a high possibility that a gap will be formed between the adhesive 3 and the second substrate 17 in the wafer central chip 16, so that a starting point 2 of a communicating void may occur in the wafer central chip 16. In such a case, it is also possible to choose to provide a convex-convex portion on the wafer center chip 16 and not provide any convex portion on the wafer outer peripheral chip 15 as before. In this way, by providing the convex portions only in the necessary areas at the necessary locations, the effects of the present invention can be obtained without causing concerns about adhesion in other areas.

(19th embodiment)
A nineteenth embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 22(a) is a top view, and FIG. 22(b) is a sectional view taken along the dotted line. The 20th embodiment is a form of a convex-convex portion, and shows that three different color columns 20, 20', and 20'' exist in one chip. If ink leaks between the color rows in this manner, there is a concern that color mixing will occur and print quality will deteriorate. Therefore, as shown in the figure, the present invention can be implemented only between color rows 20 and 20' and between color rows 20' and 20''. By providing the convex portions in the necessary locations and only in the necessary areas, the present invention can be implemented without worrying about adhesion.

(Twentieth embodiment)
A 20th embodiment will be described. The same reference numerals are given to the same parts in the first embodiment, and the description thereof will be omitted. FIG. 23(a) is a top view, and FIG. 23(b) is a sectional view taken along the dotted line. This embodiment is a form of a convex-convex portion, and shows that three different color columns 20, 20', and 20'' exist in one chip. If there is a concern that ink may leak toward the outer periphery of the chip in such a configuration, the present invention can be implemented only on the outer periphery of the chip as shown in the figure. By providing the convex portions in the necessary locations and only in the necessary areas, the present invention can be implemented without worrying about adhesion.

(Protrusion manufacturing method)
FIG. 24 shows a method of manufacturing the first convex portion 7 having a rectangular cross section. First, as shown in FIG. 24(a), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 24(b), the first substrate 1 is processed by applying the etching component 10 from above the photoresist 6. The etching component 10 is a general dry etching gas or the like. Finally, as shown in FIG. 24(c), the photoresist 6 is removed to obtain a desired rectangular convex portion.

FIG. 25 shows a method of manufacturing the first convex portion 7 having curved side surfaces. First, as shown in FIG. 25(a), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 25(b), the first substrate 1 is processed by applying an etching component 10' from above the photoresist 6. The etching component 10' is a general wet etching solution or the like. Finally, as shown in FIG. 25(c), by removing the photoresist 6, a convex portion having a desired curved side surface is obtained.

FIG. 26 shows a method of manufacturing the first convex portion 7 having an uneven shape on the side surface. First, as shown in FIG. 26(a), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 26(b), the first substrate 1 is processed by applying an etching component 10'' from above the photoresist 6. The etching component 10'' uses the Bosch process, and the resulting scalloped shape is used as the unevenness on the side surface. Finally, as shown in FIG. 26(c), by removing the photoresist 6, a convex portion having a desired uneven shape on the side surface is obtained.

FIG. 27 shows another method of manufacturing the first convex portion 7 having a rectangular cross section. First, as shown in FIG. 27(a), a processed member 12 is formed on the surface of the first substrate 1. The processed member 12 is a portion that will later become a convex portion, and can be selected from a metal film, resin, or the like. Next, as shown in FIG. 27(b), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 27C, the first substrate 1 is processed by applying the etching component 10 from above the photoresist 6. The etching component 10 is a general dry etching gas or the like, and can be selected depending on the type of workpiece 12. Finally, as shown in FIG. 27(d), the photoresist 6 is removed to obtain a desired rectangular convex portion.

FIG. 28 shows a method of manufacturing the recess 9 having a rectangular cross section. First, as shown in FIG. 28(a), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 28(b), the first substrate 1 is processed by applying the etching component 10 from above the photoresist 6. The etching component 10 is a general dry etching gas, a wet etching liquid, or the like. Finally, as shown in FIG. 28(c), the photoresist 6 is removed to obtain the desired rectangular recess 9.

FIG. 29 shows a method of manufacturing a recess 9 having a trapezoidal cross section. First, as shown in FIG. 29(a), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. At this time, in order to taper the resist pattern itself, a gradation mask or the like is used to form an inclined resist pattern. Next, as shown in FIG. 29(b), the first substrate 1 is processed by applying the etching component 10 from above the photoresist 6. By etching through the inclined resist pattern, the shape of the concave structure also becomes tapered. The etching component 10 is a general dry etching gas, a wet etching liquid, or the like. Finally, as shown in FIG. 29(c), the photoresist 6 is removed to obtain the desired trapezoidal recess 9.

FIG. 30 shows another method of manufacturing the recess 9 having a rectangular cross section. First, as shown in FIG. 30(a), a processed member 12 is formed on the surface of the first substrate 1. The processed member 12 is a portion that will later become a concave structure, and may be made of a metal film, resin, or the like. Next, as shown in FIG. 30(b), a photoresist 6 is formed on the surface of the first substrate 1, and a desired resist pattern shape is obtained by performing exposure, development, etc. Next, as shown in FIG. 30(c), the first substrate 1 is processed by applying the etching component 10 from above the photoresist 6. The etching component 10 is a general dry etching gas, a wet etching liquid, etc., and is changed depending on the material of the workpiece 12. Finally, as shown in FIG. 30(d), the photoresist 6 is removed to obtain the desired rectangular recess 9.

(Example)
An example of manufacturing the first embodiment will be described. First, a first substrate 1 and a second substrate 17, each of which has a flow path 4 formed on a silicon substrate, are prepared. Next, resist patterning, etching, etc. were performed on the bonding surface of the first substrate 1 at a desired position to obtain a first convex portion 7 having a height of 3 μm. Next, resist patterning, etching, etc. were performed on the bonding surface of the element substrate at a desired position to obtain a second convex portion 8 having a height of 3 μm. Adhesive 3 was directly drawn on the bonding surface of first substrate 1 to a height of 5.5 μm. Thereafter, the first substrate 1 and the second substrate 17 were bonded using a bonding device. At this time, the height of the adhesive layer 11 was 5 μm. Thereafter, the entire channel member was heat-treated at 200° C. for 1 hour, thereby making it possible to obtain a desired channel member bonded with an adhesive layer without communicating voids 5.

Note that the shapes shown in this example are merely examples, and configurations obtained by combinations of the shapes shown in the embodiments are also included as part of the present invention. Further, although an example is shown in which substrates are bonded using an adhesive, the present invention can also be applied to similar applications such as bonding chips and chip units with a sealing material.

1 First substrate 3 Adhesive 7 First convex portion 8 Second convex portion 17 Second substrate 23 First surface 24 Second surface

Claims (16)

a first substrate having a first surface;
a second substrate having a second surface opposite to the first surface;
Equipped with
In a liquid ejection head in which the first substrate and the second substrate are joined via an adhesive between the first surface and the second surface,
A first convex portion protruding toward the second surface is formed on the first surface,
A liquid ejection head characterized in that the second surface is provided with a second convex portion that protrudes toward the first surface. 2. The total height of the first convex portion from the first surface and the height of the second convex portion from the second surface is greater than or equal to the thickness of the adhesive. liquid ejection head. 3. The liquid ejection head according to claim 1, wherein side surfaces of the first convex portion and the second convex portion are curved. 4. The height of the first convex portion from the first surface and the height of the second convex portion from the second surface are different. Liquid ejection head. The liquid ejection head according to claim 1, wherein side surfaces of the first convex portion and the second convex portion have an uneven shape. The liquid ejection head according to claim 1, wherein the first convex portion and the second convex portion have a trapezoidal cross-sectional shape. The liquid ejection head according to claim 1, wherein the first convex portion and the second convex portion have a triangular cross-sectional shape. A channel opening is formed in the first substrate and the second substrate,
8. The liquid ejection head according to claim 1, wherein the first protrusion and the second protrusion surround the opening. The liquid ejection head according to claim 8, wherein the first convex portion and the second convex portion continuously surround the opening. The liquid ejection head according to claim 8, wherein the first convex portion and the second convex portion intermittently surround the opening. 11. The liquid ejection head according to claim 1, wherein an escape groove for the adhesive is formed in at least one of the first substrate and the second substrate. The liquid ejection head according to claim 11, wherein the first convex portion and the second convex portion are formed along the relief groove. A plurality of the first protrusions and the second protrusions are formed. a first substrate having a first surface;
a second substrate having a second surface opposite to the first surface;
Equipped with
In a liquid ejection head in which the first substrate and the second substrate are joined via an adhesive between the first surface and the second surface,
A convex portion protruding toward the second surface is formed on the first surface,
A recess is formed on the second surface at a position opposite to the first convex part,
A liquid ejection head characterized in that a portion of the convex portion is inserted into the concave portion. The liquid ejection head according to claim 14, wherein the width of the concave portion is wider than the width of the convex portion. The liquid ejection head according to claim 14 or 15, wherein the convex portion and the concave portion have a trapezoidal cross-sectional shape.

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