Liquid discharge head

Abstract

To provide a liquid discharge head that can suppress inflow of air bubbles into a pressure chamber while improving refill performance.SOLUTION: A liquid discharge head includes: a discharge port for discharging liquid; a pressure generating element for generating pressure to discharge liquid from the discharge port; a pressure chamber on which pressure by the pressure generating element acts; and a base plate formed with a supply port for supplying liquid to the pressure chamber. A bent part and a corner part are formed in an end part of the surface on the pressure chamber side among the surfaces of the base plate.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] A liquid ejection head used in a liquid ejection device such as an inkjet printer normally generates energy for ejection from an energy generating element provided in a pressure chamber, and ejects liquid from an ejection port. In order to achieve even higher speed recording with a liquid ejection device, it is required to quickly replenish (refill) the liquid after ejection from the ejection port. If the liquid is not refilled sufficiently, there is a concern that adverse effects such as impaired ejection stability may occur.

[0003] In Patent Document 1, a part of an insulating layer formed on a substrate is removed by etching to expand the cross-sectional area of ​​the liquid flow path, thereby improving liquid refilling. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7171426 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the method described in Patent Document 1, since only the insulating layer formed on the substrate is removed, there is a limit to expanding the cross-sectional area of ​​the liquid flow path. Therefore, it may be difficult to further improve the refill performance. In addition, the problem of air bubbles flowing into the pressure chamber increasing even though the refill performance is improved by the method according to Patent Document 1 still remains.

[0006] In view of the above-mentioned problems, an object of the present invention is to provide a liquid ejection head that can further improve refilling performance while suppressing the inflow of air bubbles into a pressure chamber. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a liquid ejection head having a substrate in which an ejection port for ejecting liquid and a supply port for supplying liquid to the ejection port are formed, and an insulating layer formed on the substrate, the insulating layer having an energy generating element that generates energy for ejecting liquid from the ejection port, wherein the end of the substrate on the supply port side has a curved portion and a corner. Effect of the Invention

[0008] According to the present invention, it is possible to provide a liquid ejection head that can further improve the refilling performance and prevent air bubbles from flowing into the pressure chamber. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a liquid ejection head according to a conventional example. [Diagram 2] FIG. 1 is a schematic diagram showing a liquid ejection head according to a first embodiment. [Diagram 3] FIG. [Figure 4] FIG. 11 is a schematic diagram showing a liquid ejection head according to a second embodiment. [Diagram 5] FIG. 11 is a schematic diagram showing a liquid ejection head according to a third embodiment. [Figure 6] FIG. 13 is a schematic diagram showing a liquid ejection head according to a fourth embodiment. [Figure 7] FIG. 13 is a schematic diagram showing a liquid ejection head according to a modified example of the fourth embodiment. [Figure 8] FIG. 13 is a schematic diagram showing the state of air bubbles in a conventional example. [Figure 9] Schematic diagram showing the state of bubbles in the present embodiment. FIG. [Figure 10] FIG. 13 is a schematic diagram showing a liquid ejection head according to a fifth embodiment. [Figure 11] FIG. 13 is a schematic diagram showing a liquid ejection head according to a sixth embodiment. [Figure 12] FIG. 13 is a schematic diagram showing a liquid ejection head according to a seventh embodiment. [Figure 13] FIG. 13 is a schematic view showing a liquid ejection head according to the eighth to eleventh embodiments. [Figure 14] Schematic diagram illustrating the effect of the present invention. [Figure 15] Schematic diagram illustrating the effect of the present invention. [Figure 16] Schematic diagram showing a manufacturing method. [Figure 17] Schematic diagram showing a manufacturing method. [Figure 18] Schematic diagram showing a manufacturing method. [Figure 19] FIG. [Figure 20] FIG. [Figure 21] FIG. [Figure 22] FIG. [Figure 23] FIG. [Figure 24] FIG. [Diagram 25] FIG. [Figure 26] FIG. [Figure 27] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted.

[0011] (First embodiment) The liquid ejection head using this embodiment is mounted on an inkjet printer (not shown). There are various types of inkjet printers, but generally, the printer is provided with a carriage (not shown) that can move in the scanning direction, and the carriage is provided with a liquid ejection head that ejects liquid 16 onto a printing medium. The liquid 16 is delivered from an ink tank, and is replenished into the pressure chamber 10 through the cover plate opening 14, the common flow path 17, and the inlet 8. When printing, the liquid 16 that has been replenished into the pressure chamber 10 is ejected onto a print target through the ejection port 6 by energy provided by the energy generating element 4. By repeating the scanning and ejection of the carriage, a desired print pattern is printed. In addition, in the case of a configuration capable of liquid circulation, a recovery port 9 is further provided, and when the liquid 16 is circulated in the liquid flow path in order to suppress the viscosity of the liquid 16 without ejection, the liquid 16 is returned to the common flow path 17 through the recovery port 9.

[0012] FIG. 1 shows a liquid ejection head using a conventional technique. FIG. 1(a) is a plan view enlarging the vicinity of the surface of a substrate 3, and FIG. 1(b) is a cross-sectional view at the position AA in FIG. 1(a), showing a part of the liquid ejection head. An energy generating element 4 is provided on the substrate 3, and a flow path member 1 is formed thereon to define a liquid flow path and a pressure chamber 10. Furthermore, an inlet 8 and a recovery port 9 are formed on the substrate 3, and the flow direction and flow rate 7 of the liquid are shown by arrows in the figure, indicating that there is a flow from the inlet 8 to the recovery port 9. A part of the insulating layer 2 has been removed by etching, and the cross-sectional area of ​​the flow path has increased accordingly. A corner 12 is present on the same surface of the substrate 4 as the energy generating element 4.

[0013] FIG. 2 shows a first embodiment of the present invention. FIG. 2(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 2(b) is a cross-sectional view at the position BB in FIG. 2(a), in which a part of the liquid ejection head is extracted. As shown in FIG. 2(b), a curved portion 11 and a corner portion 12 that were not present in FIG. 1(b) are present by etching a part of the substrate 3 upstream of the pressure chamber 10. The curved portion 11 and the corner portion 12 are basically required to be present on the surface layer of the substrate 3 in order to obtain the effect of the present invention by contacting the liquid. In FIG. 2, the curved portion 11 and the corner portion 12 are formed on the upstream side of the pressure chamber 10 in the flow direction in which the liquid flows. Next, FIGS. 2(c) and (d) are cross-sectional views showing a modified example of FIG. 2(b), and by increasing the amount of etching of the substrate 3, the flow channel cross-sectional area can be increased more than that of FIG. 2(b). In addition, air bubbles are caught by the corner portion 12 present in the liquid flow channel, preventing them from being sent to the pressure chamber 10 beyond. Since the corner portion 12 is farther from the pressure chamber 10 and the ejection port 6 than in the past, deterioration of print quality due to air bubbles can be made less likely to occur.

[0014] FIG. 3 is a diagram for explaining the definition of the curved portion 11 in the present invention. To begin with, the curved portion 11 is formed by etching or the like at least in part of the portion of the substrate 1 that corresponds to the liquid flow path. The corner portion 12 is an angled structural portion that occurs at the boundary between the region to be etched and the region not to be etched as described above. Both of these achieve the effect of the invention by directly contacting the liquid 16. Next, the definition of the curved portion 11 will be explained. As shown in FIG. 3, first, a dashed imaginary right-angled triangle is placed along the corner portion 12 in the cross-sectional view of the curved portion 11. At this time, the first requirement is that the depth direction Z corresponding to the short side of the triangle is 1 μm or more (A). Next, the second requirement is that the sum of the two angles of the corner portion 12 that is the end of the curved portion 11 is greater than 270° (B). The curved portion 11 is defined as one that simultaneously satisfies A and B.

[0015] Second Embodiment FIG. 4 shows a second embodiment of the present invention. FIG. 4(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 4(b) is a cross-sectional view taken at the position C-C in FIG. 4(a), showing a part of the liquid ejection head. As shown in FIG. 4(b), a curved portion 11 and a corner portion 12 are present downstream of the pressure chamber 10 by etching a part of the substrate 3. FIG. 4(c) is a cross-sectional view showing a modified example of FIG. 4(b), and the flow path cross-sectional area can be increased compared to FIG. 4(b) by increasing the amount of etching of the substrate 3. By increasing the flow path cross-sectional area on the downstream side, the amount of liquid 16 discharged from the pressure chamber 10 to the recovery port 9 can be increased. By discharging the liquid 16 from the pressure chamber 10, the amount of liquid 16 flowing into the pressure chamber 10 from the inlet 8 can be increased.

[0016] (Third embodiment) FIG. 5 shows a third embodiment. FIG. 5(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 5(b) is a cross-sectional view at the position D-D in FIG. 5(a), in which a part of the liquid ejection head is extracted. As shown in FIG. 5(b), a curved portion 11 and a corner portion 12 are present on both the upstream side and the downstream side of the pressure chamber 10 by etching a part of the substrate 3. FIG. 5(c) is a cross-sectional view showing a modified example of FIG. 5(b), in which the flow channel cross-sectional area can be increased more than that of FIG. 5(b) by increasing the amount of etching of the substrate 3. By increasing the flow channel cross-sectional area on both the upstream side and the downstream side, the amount of liquid 16 supplied from the inlet 9 to the pressure chamber 10 and the amount of liquid 16 discharged from the pressure chamber 10 to the recovery port 9 can be efficiently increased. By increasing the flow rate on the inlet side and the outlet side of the pressure chamber 10 to the same extent, stagnation due to the difference in flow rate can be prevented.

[0017] (Fourth embodiment) FIG. 6 shows a fourth embodiment. FIG. 6(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 6(b) is a cross-sectional view at the position EE in FIG. 6(a), in which a part of the liquid ejection head is extracted. As shown in FIG. 6(b), a curved portion 11 and two corners 12 are present by etching a part of the substrate 3 upstream of the pressure chamber 10. The air bubble 15 is caught by each of the two corners 12 present in the liquid flow path, preventing the air bubble 15 from being supplied to the pressure chamber 10 beyond. In the liquid flow path from the inlet 8 to the pressure chamber 10, the number of corners 12 is increased compared to the first embodiment, so that the air bubble 15 can be more easily caught. Therefore, it is possible to make it more difficult for the print quality to be deteriorated by the air bubble 15. FIG. 6(c) and FIG. 6(d) are cross-sectional views showing a modified example of FIG. 6(b), and the flow path cross-sectional area can be increased more than that of FIG. 6(b) by increasing the amount of etching of the substrate 3. This makes it possible to simultaneously obtain effects on both the flow rate issue and the issue of air bubbles 15. In addition, since the corners 12 are far from the pressure chambers 10 and the ejection ports 6, it is possible to make it more difficult for deterioration of print quality due to air bubbles 15 to occur. The embodiment can be appropriately selected depending on the content of the issue to be solved, etc.

[0018] FIG. 7 shows one aspect of the fourth embodiment of the present invention, where FIG. 7(a) is a plan view showing a configuration in which liquid is supplied from two inlets to one pressure chamber, and FIG. 7(b) is a cross-sectional view taken along the line F-F in FIG. 7(a). The shape is similar to that of the fourth embodiment, but an inlet 8 exists at the location of the recovery port 9. In this case, although there is no liquid circulation function, liquid 16 is supplied from both the left and right sides, improving the refillability of the pressure chamber 10. FIG. 7(c) is a plan view showing a configuration in which liquid is supplied from one inlet to one pressure chamber and no recovery port is provided, and FIG. 7(d) is a cross-sectional view taken along the line G-G in FIG. 7(c).

[0019] This one also does not have a recovery port 9, and the liquid flow path and inlet port 8 are only on the right side of the pressure chamber 10. Even in this type of configuration, the demand for improved refillability is still increasing day by day, but by implementing the present invention, it is possible to similarly improve the refillability.

[0020] FIG. 8 is a diagram for explaining the movement and growth of gas dissolved in liquid in a conventional embodiment. First, as shown in FIG. 8(a), as an example, three bubbles 15 are shown inside the inlet 8. Next, as shown in FIG. 8(b), it is known that the bubbles 15 dissolved in the liquid 16 grow as the liquid 16 moves along the wall surface of the liquid flow path. The grown bubbles 15 run along the wall surface of the inlet 8, while the other bubbles 15 move further toward the pressure chamber 10 while remaining dissolved in the liquid 16. At that time, the flow direction of the liquid is not only vertical or horizontal, but also diagonal as shown in the figure. Then, as shown in FIG. 8(c), in the conventional embodiment, the wall surface or corner 12 acts as a resistance against the bubbles 15 for some of the bubbles 15, and the bubbles 16 are caught especially at the corner where the flow vector changes, and do not move thereafter. Therefore, some of the bubbles 15 stay in front of the pressure chamber 10. However, most of the other bubbles 15 flow into the pressure chamber 10 following the flow of the liquid 16.

[0021] FIG. 9 is a diagram for explaining that the fourth embodiment has improved trapping ability of bubbles 15 in a form having multiple corners 12. As shown in FIG. 9(a), as an example, three bubbles 15 are present inside the inlet 8. Next, as shown in FIG. 9(b), the bubbles 15 dissolved in the liquid 16 grow as the liquid 16 moves along the wall surface of the liquid flow path. The grown bubbles 15 run along the wall surface of the inlet 8, and the remaining bubbles 15 move further toward the pressure chamber 10 while remaining dissolved in the liquid 16. At that time, the liquid flows not only vertically or horizontally, but also diagonally as shown in the figure. Then, as shown in FIG. 9(c), in the fourth embodiment of the present invention, the wall surface or the corners 12 act as resistance bodies against some of the bubbles 15, and the bubbles 15 are more likely to get caught by the corners 12, especially at the corners where the vector of the flow changes. Once caught, the bubbles 15 do not move thereafter. In the fourth embodiment, the presence of multiple corners 12 increases the number of resistors on which the air bubbles 15 get caught, so that more air bubbles 15 are retained in front of the pressure chamber 10 than in the conventional embodiment. In this way, by implementing the present invention, it is possible to improve the refillability while also exerting the effect of suppressing the inflow of air bubbles 15 into the pressure chamber 10.

[0022] Fifth embodiment FIG. 10 shows the fifth embodiment. FIG. 10(a) is an enlarged plan view of the surface of the substrate 3, and FIG. 10(b) is a cross-sectional view at the position HH in FIG. 10(a), showing a part of the liquid ejection head. As shown in FIG. 10(b), a curved portion 11 and three corners 12 are present by etching a part of the substrate 3 upstream of the pressure chamber 10. FIGS. 10(c) and 10(d) are diagrams explaining that the trapping ability of the air bubble 15 is improved by increasing the number of corners 12 to three. As shown in FIG. 10(c), as an example, a state in which three air bubbles 15 exist inside the inlet 8 is shown.

[0023] The bubbles 15 dissolved in the liquid 16 grow as the liquid 16 moves along the wall of the liquid flow path. The grown bubbles 15 move along the wall of the inlet 8, while the remaining bubbles 15 move further toward the pressure chamber 10 while remaining dissolved in the liquid 16. In this case, the liquid flows not only vertically or horizontally, but also diagonally as shown in the figure.

[0024] Next, as shown in FIG. 10(d), in the fifth embodiment of the present invention, the wall surface or the corners 12 of some of the bubbles 15 become resistance bodies against the bubbles 15, and the bubbles 15 are more likely to get caught by the corners 12, especially at the corners where the vector of the flow changes. The number of corners 12 is increased compared to the fourth embodiment, which prevents the bubbles 15 from being sent to the pressure chamber 10 ahead. Once the bubbles 15 get caught, they do not move thereafter. The presence of multiple corners 12 increases the number of resistance bodies that the bubbles 15 get caught on, so that more bubbles 15 stay in front of the pressure chamber 10 than in the conventional embodiment. In this way, by implementing this embodiment, it is possible to improve the refillability while also exerting the effect of suppressing the inflow of the bubbles 15 into the pressure chamber 10. In other words, it is possible to make it more difficult for the bubbles 15 to cause a decrease in print quality.

[0025] Sixth embodiment FIG. 11 shows a sixth embodiment. FIG. 11(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 11(b) is a cross-sectional view at the position II in FIG. 11(a), in which a part of the liquid ejection head is extracted. As shown in FIG. 11(b), a curved portion 11 and two corners 12 are present by etching a part of the substrate 3 downstream of the pressure chamber 10. FIG. 11(c) is a cross-sectional view showing a modified example of FIG. 11(b), in which the flow path cross-sectional area can be increased more than that of FIG. 11(b) by increasing the amount of etching of the substrate 3. By increasing the flow path cross-sectional area on the downstream side, the amount of liquid 16 discharged from the pressure chamber 10 to the recovery port 9 can be increased. Discharge of the liquid 16 from the pressure chamber 10 also indicates that the amount of liquid 16 flowing into the pressure chamber 10 from the inlet 8 can be increased.

[0026] Seventh embodiment FIG. 12 shows a seventh embodiment. FIG. 12(a) is a plan view enlarging the vicinity of the surface of the substrate 3, and FIG. 12(b) is a cross-sectional view at the position J-J in FIG. 12(a), showing a part of the liquid ejection head. As shown in FIG. 12(b), a curved portion 11 and two corners 12 are present on both the upstream side and the downstream side of the pressure chamber 10 by etching a part of the substrate 3. FIG. 12(c) is a cross-sectional view showing a modified example of FIG. 12(b), and the flow path cross-sectional area can be increased more than that of FIG. 12(b) by increasing the amount of etching of the substrate 3. By increasing the flow path cross-sectional area on both the upstream side and the downstream side, the amount of liquid 16 discharged from the pressure chamber 10 to the recovery port 9 can be efficiently increased. By increasing the flow rate on the inflow side and the outflow side of the pressure chamber 10 to the same extent, stagnation due to the difference in flow rate can be prevented.

[0027] (Eighth to Eleventh Embodiments) Fig. 13 is a plan view showing embodiments with different shapes in the horizontal direction (XY direction), Fig. 13(a) shows an eighth embodiment, Fig. 13(b) shows a ninth embodiment, Fig. 13(c) shows a tenth embodiment, and Fig. 13(d) shows an eleventh embodiment. Although cross-sectional views are omitted, the cross-sectional shape of Fig. 6(b) is very similar due to the presence of multiple corners 12 on the upstream side. Fig. 6(a) shows an example of the position (shape) of the corners 12 in the horizontal direction (XY direction), and the shape is an arc in the horizontal direction (XY direction).

[0028] In contrast, the eighth embodiment in FIG. 13(a) is linear, and approximately half of the flat area of ​​the substrate 3 is curved portion 11. By making the boundary linear, the present invention can be practiced with good reproducibility, regardless of the etching or the resolution of the pattern of the etching-resistant resist used in the etching. The ninth embodiment in FIG. 13(b) is linear, and approximately three-quarters of the flat area of ​​the substrate 3 is curved portion 11. By expanding the area of ​​the curved portion 11, it is possible to increase not only the amount of etching in the vertical direction (Z direction) but also the amount of etching in the horizontal directions (XY directions).

[0029] The difference from the first embodiment is that there are more corners 12. The tenth embodiment in FIG. 13(c) is arc-shaped, and there is one curved portion 11 for each inlet 8. This embodiment has the advantage that it can be easily formed using the manufacturing method shown in FIG. 18 without adding any additional steps. The eleventh embodiment in FIG. 13(d) is arc-shaped, and there are two curved portions 11 for each inlet 8. By providing the curved portion 11 closer to the outlet 4, it is easier to affect the flow from the inlet 8 to the pressure chamber 10, and the effect of the present invention can be obtained more effectively.

[0030] Fig. 14 is a diagram explaining a further effect of applying the present invention only to the end portions of the same row, Fig. 14(a) is a plan view showing an example of the problem, and Fig. 14(b) is a cross-sectional view taken along the line K-K in Fig. 14(a). As shown in Fig. 14(b), liquid 16 passes through cover plate opening 14, and in the region surrounded by common flow path 17 and cover plate 13, flows as shown by the liquid flow direction and flow rate 7, passes through inlet 8, and then heads toward pressure chamber 10. When passing through inlet 8, if the shape is the same, the same amount of flow loss will occur, and the flow rate to pressure chamber 10 will be further reduced.

[0031] As a result, there is a problem that the flow rate at the end of the row is lower than that at other parts of the same row. This state is also shown in FIG. 14(a). If printing is performed continuously under such a condition, there is a risk that insufficient refilling will occur at the end of the row, resulting in a decrease in print quality. Therefore, as shown in FIG. 14(c) and (d), bends and corners can be provided only at the end of the row. FIG. 14(c) is a plan view showing the state in which the present invention is implemented at the end of the row, and FIG. 14(d) is a cross-sectional view at the position L-L in FIG. 14(c). In the pressure chamber 10 in which this embodiment is implemented, the loss of flow rate when the liquid passes through the inlet 8 can be made smaller than in other parts, so the flow rate in the pressure chamber 10 can be made uniform between the end of the row and the other parts.

[0032] FIG. 15 is a diagram for explaining further effects by applying a plurality of types of embodiments in the same row, FIG. 15(a) is a plan view showing an example of a problem, and FIG. 15(b) is a cross-sectional view at the position M-M in FIG. 15(a). As shown in FIG. 15(b), the liquid 16 passes through the cover plate opening 14, flows in the area surrounded by the common flow path 17 and the cover plate 13 as shown by the liquid flow direction and flow rate 7, passes through the inlet 8, and further travels toward the pressure chamber 10. The cover plate opening 14 is restricted in position and size, and cannot be freely configured. Therefore, a place far from the cover plate opening 14 and a place close to it are generated in stages for each position of the inlet 8. In a place far from the cover plate opening 14, the flow rate may gradually decrease even in the common flow path 17 depending on the distance. When passing through the inlet 8, if the shape is the same, the same amount of flow rate loss is incurred, and the flow rate to the pressure chamber 10 is further reduced.

[0033] As a result, there is a problem that the flow rate decreases stepwise depending on the distance in locations far from the cover plate opening 14. This state is also shown in Figure 15(a). If printing is performed continuously under such conditions, there is a risk that insufficient refilling will occur in locations far from the cover plate opening 14, resulting in a deterioration of print quality over a wide area. Therefore, as shown in Figures 15(c) and (d), the present invention can be applied in different embodiments stepwise even within the same row.

[0034] 15(c) is a plan view showing the state in which the present invention is applied to the end of the row, and FIG. 14(d) is a cross-sectional view taken along the line N-N in FIG. 14(c). In the example shown in FIG. 15(c), no application is made to the area close to the cover plate opening 14, a modified version of the fourth embodiment shown in FIG. 6(c) is applied to a relatively close area, and a modified version of the fourth embodiment shown in FIG. 6(d) is applied to a far area. As a result, as shown in FIG. 15(d), by applying different embodiments of the present invention as appropriate depending on the area, the loss of flow rate when the liquid passes through the inlet 8 in the pressure chamber 10 can be reduced more than in other areas, and the flow rate in the pressure chamber 10 can be made uniform within the same row.

[0035] (Other embodiments) 19 to 27 are schematic diagrams showing other embodiments of the present invention. In Fig. 19, among the multiple curved portions formed, the first curved portion 11a and the second curved portion 11b have different deepest positions in the direction perpendicular to the substrate. As shown in Fig. 19, the present invention may have a form in which the deepest positions of the curved portions differ depending on the location.

[0036] In Fig. 20, among the multiple corners formed, a first corner 12a and a second corner 12b are shown to be in different positions in the direction perpendicular to the substrate. As shown in Fig. 20, the present invention may be configured such that the positions of the corners vary depending on the location.

[0037] In Fig. 21, a curved portion row is formed by forming a plurality of curved portions 11 along a plurality of pressure chambers 10. In the curved portion row, the position of the deepest part in the direction perpendicular to the substrate of the curved portions is different between the curved portions located at the ends of the curved portion row and the curved portions located other than the ends. As shown in Fig. 21, the present invention may have a different depth between the ends and other parts.

[0038] 22, a curved portion row is formed by forming a plurality of curved portions 11 along a plurality of pressure chambers 10. In the curved portion row, the curved portion 11a, whose deepest position in the direction perpendicular to the substrate is located at the end of the curved portion row, shows the deepest form. This makes it possible to improve the refill performance of the supply port at the end where the liquid refill performance may be the lowest.

[0039] 23, a corner row is formed by forming a plurality of corners 12 along a plurality of pressure chambers 10. In the corner row, the positions of the corners 12 in the direction perpendicular to the substrate are different between corners 12a located at the ends of the corner row and corners 12b located other than the ends. As shown in FIG. 23, the present invention may have corners located at different positions between the ends and other than the ends.

[0040] 24, a corner row is formed by forming a plurality of corners 12 along a plurality of pressure chambers 10. In the corner row, a corner 12a located at the end of the corner row, in terms of its position in the direction perpendicular to the substrate, is the deepest. This makes it possible to improve the refill performance of the supply port at the end where the liquid refill performance is likely to be the lowest.

[0041] 25 shows a state in which a cover plate 13 is formed on the back surface of the substrate on the pressure chamber side. A plurality of curved portions 11 are formed along the plurality of pressure chambers 10 to form a curved portion row. In the curved portion row, the position of the deepest part of the curved portion 11 in the direction perpendicular to the substrate becomes deeper in stages according to the distance from the opening 14 of the cover plate 13. As a result, since there is a risk that the refill performance of the supply port located far from the opening 14 is low, by making the curved portion located far from the opening 14 deeper, it is possible to improve the refill performance from the supply port located far from the opening 14.

[0042] 26, a plurality of corners 12 are formed along a plurality of pressure chambers 10, and the distances of the corners from the pressure generating element 4 differ between a first corner 12a and a second corner 12b among the plurality of corners. As shown in FIG. 26, in the present invention, the distances of the corners from the pressure generating element 4 may differ.

[0043] 27, a corner row is formed by forming a plurality of corners 12 along a plurality of pressure chambers 10. In the corner row, the distance from the pressure generating element 4 to the corners is different between a corner 12b located at the end of the corner row and a corner located other than the end.

[0044] (First manufacturing method) FIG. 16 shows how the first embodiment is formed using the first manufacturing method. As shown in FIG. 16(a), a substrate 3 on which an energy generating element 4, a wiring layer 5, and an insulating layer 2 are applied in advance is prepared. A desired pattern is formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain a recessed portion of the insulating layer 2. Next, as shown in FIG. 16(b), a desired pattern is further formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain through holes for the inlet 8 and the recovery port 9. Next, as shown in FIG. 16(c), a pattern of the etching-resistant resist 18 formed using a gradation mask or the like is formed at a position corresponding to the curved portion. Then, an etchant 19 is applied by dry etching or the like to obtain a desired curved portion 11 and a corner portion 12 as shown in FIG. 16(d).

[0045] (Second manufacturing method) FIG. 17 shows how the fourth embodiment is formed using the second manufacturing method. As shown in FIG. 17(a), a substrate 3 on which an energy generating element 4, a wiring layer 5, and an insulating layer 2 are applied in advance is prepared. A desired pattern is formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain a recessed portion of the insulating layer 2. Next, as shown in FIG. 17(b), a desired pattern is further formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain through holes for the inlet 8 and the recovery port 9. Next, as shown in FIG. 17(c), a pattern of the etching-resistant resist 18 is formed using a gradation mask or the like at a position corresponding to the curved portion. Then, an etchant 19 is applied by dry etching or the like to obtain a desired curved portion 11 and a corner portion 12 as shown in FIG. 17(d).

[0046] (Third manufacturing method) FIG. 18 shows how the fourth embodiment is formed using the third manufacturing method. As shown in FIG. 18(a), a substrate 3 on which an energy generating element 4, a wiring layer 5, and an insulating layer 2 are applied in advance is prepared. A desired pattern is formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain a recessed portion of the insulating layer 2. Next, as shown in FIG. 18(b), a desired pattern is further formed thereon with an etching-resistant resist 18, and an etchant 19 is applied by dry etching or the like to obtain through holes for the inlet 8 and the recovery port 9. Next, as shown in FIG. 18(c), further etching is performed, causing an action 20 of the etchant due to a loading effect, and the substrate 3 is further etched. As a result, a desired curved portion 11 and a corner portion 12 can be obtained as shown in FIG. 18(d).

[0047] (Example) First, a substrate 3 was prepared, which was a silicon substrate provided with energy generating elements 4 and the like. The substrate was repeatedly subjected to desired resist patterning and etching to provide an inlet 8 and a recovery port 9. Furthermore, patterning and etching were performed to form a curved portion 11, resulting in a curved portion 11 with a maximum depth of 10 μm and a corner portion 12. Thereafter, a flow path member 1 was formed on the substrate 3, and the flow path member was patterned, etc., to obtain the desired shape of the liquid ejection head. [Explanation of symbols]

[0048] 3. Substrate 4 Pressure generating element 6 Outlet 10 Pressure Chamber 11 Curved section 12 Corner

Claims

1. A discharge port for discharging liquid; a pressure generating element that generates pressure for ejecting liquid from the ejection port; a pressure chamber to which pressure from the pressure generating element acts; a substrate having a supply port formed therein for supplying liquid to the pressure chamber; In a liquid ejection head having A liquid ejection head, characterized in that a curved portion and a corner portion are formed at an end portion of the surface of the substrate on the side of the pressure chamber.

2. 2. The liquid ejection head according to claim 1, wherein the curved portion and the corner portion are formed on the upstream side of the pressure chamber in the flow direction of the liquid flowing on the substrate.

3. a recovery port for recovering liquid not discharged from the discharge port is formed in the substrate; The liquid ejection head according to claim 1 , wherein the curved portion and the corner portion are formed on the downstream side of the pressure chamber in the flow direction of the liquid flowing on the substrate.

4. a recovery port for recovering liquid not discharged from the discharge port is formed in the substrate; 2. The liquid ejection head according to claim 1, wherein the curved portion and the corner portion are formed on both the upstream side and the downstream side of the pressure chamber in the flow direction of the liquid flowing on the substrate.

5. the substrate is provided with a plurality of curved portions and a plurality of corners along the plurality of pressure chambers, The liquid ejection head according to claim 1 , wherein the deepest positions of the curved portions in a direction perpendicular to the substrate are different between a first curved portion and a second curved portion among the plurality of curved portions.

6. the substrate is provided with a plurality of curved portions and a plurality of corners along the plurality of pressure chambers, The liquid ejection head according to claim 1 , wherein a first corner and a second corner of the plurality of corners are different in position in a direction perpendicular to the substrate.

7. a curved portion row is formed on the substrate by forming a plurality of the curved portions along the plurality of the pressure chambers, A liquid ejection head as described in claim 1 , wherein within the curved portion row, the position of the deepest part of the curved portion in a direction perpendicular to the substrate is different between the curved portion located at the end of the curved portion row and the curved portion located other than the end.

8. a curved portion row is formed on the substrate by forming a plurality of the curved portions along the plurality of the pressure chambers, The liquid ejection head according to claim 1 , wherein the curved portion located at an end of the curved portion row has the deepest position in a direction perpendicular to the substrate within the curved portion row.

9. a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, The liquid ejection head according to claim 1 , wherein the positions of the corners in the row of corners in a direction perpendicular to the substrate are different between the corners located at the ends of the row of corners and the corners located other than the ends.

10. a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, The liquid ejection head according to claim 1 , wherein, in the row of corners, the corners located at the ends of the row of corners have the deepest positions in the direction perpendicular to the substrate.

11. a cover plate is formed on a back surface of the substrate on the pressure chamber side; a curved portion row is formed on the substrate by forming a plurality of the curved portions along the plurality of the pressure chambers, The liquid ejection head according to claim 1 , wherein the positions of the deepest parts of the curved portions in the row of curved portions in a direction perpendicular to the substrate become deeper in stages according to the distance from the opening of the cover plate.

12. A liquid ejection head as described in claim 11, wherein the deepest position of the curved portion in the row of curved portions in a direction perpendicular to the substrate is the deepest at the curved portion formed at the position farthest from the opening of the cover plate in the row of curved portions.

13. a cover plate is formed on a back surface of the substrate on the pressure chamber side; a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, The liquid ejection head according to claim 1 , wherein, in the row of corners, the positions of the corners in a direction perpendicular to the substrate become deeper in stages according to the distance from the opening of the cover plate.

14. A liquid ejection head as described in claim 13, wherein the position of the deepest part of the corner in the row of corners in a direction perpendicular to the substrate is the deepest at the corner formed at the position farthest from the opening of the cover plate in the row of corners.

15. the substrate has a plurality of corners formed along the plurality of pressure chambers, The liquid ejection head according to claim 1 , wherein a distance from the pressure generating element to the corners is different between a first corner and a second corner among the plurality of corners.

16. a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, 2. The liquid ejection head according to claim 1, wherein in the corner row, the distance from the pressure generating element to the corners differs between the corners located at the ends of the corner row and the corners located other than the ends.

17. a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, 2. The liquid ejection head according to claim 1, wherein the corners in the row are positioned at the ends of the row of corners, and the corners are positioned at the deepest distance from the pressure generating element.

18. a cover plate is formed on a back surface of the substrate on the pressure chamber side; a corner row is formed on the substrate by forming a plurality of the corners along the plurality of the pressure chambers, 2. The liquid ejection head according to claim 1, wherein, in the row of corners, the distance from the pressure generating element to the corners decreases stepwise according to the distance from the opening of the cover plate.

19. The liquid ejection head according to claim 18, wherein the distance from the pressure generating element to the corner in the row of corners is shortest at a corner formed at a position in the row of corners farthest from the opening of the cover plate.

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