JP6171051B1 - Inkjet recording head - Google Patents

Abstract

An ink jet recording head capable of ejecting ink droplets satisfactorily with a sufficient ejection pressure is provided.
An ink jet recording head includes a drive substrate 10 having a plurality of ink pressure chambers 11 extending in a first direction, a supply substrate 20 stacked on the drive substrate 10, and each ink pressure chamber 11. A plurality of nozzles 32 that communicate with each other and are respectively provided in the center in the longitudinal direction of the ink pressure chamber 11, and a plurality of piezoelectric elements 40 that pressurize ink in each ink pressure chamber 11 and eject ink droplets via the nozzles 32. And having. The supply substrate 20 communicates with one end in the longitudinal direction of the plurality of ink pressure chambers 11 and extends in a second direction intersecting the first direction, and other than the plurality of ink pressure chambers 11. An ink discharge path 24 that communicates with the end and extends in the second direction is provided.
[Selection] Figure 2

Description

  Embodiments described herein relate generally to an ink jet recording head of a type that circulates ink in an ink pressure chamber communicating with a nozzle.

  The ink jet recording head includes a nozzle that ejects ink droplets, an ink pressure chamber that communicates with the nozzle, and an actuator that pressurizes ink in the ink pressure chamber. This head drives the actuator to pressurize ink in the ink pressure chamber and eject ink droplets from the nozzles.

  As an actuator, for example, a piezoelectric type that discharges ink droplets by deforming and displacing a wall surface (vibration plate) of an ink pressure chamber using a piezoelectric element is known. Piezoelectric actuators have the advantage that there is no restriction on the type of ink used because the piezoelectric element does not directly contact the ink and the heat generation of the piezoelectric element can be ignored. Therefore, a so-called piezoelectric MEMS type ink jet recording head in which semiconductor process technology is applied to the piezoelectric type has been attracting attention.

JP 2000-263785 A JP 2008-10528 A

  When pressure is applied to the ink in the ink pressure chamber and ink droplets are ejected from the nozzles, the ink pressure in the ink pressure chamber needs to be maintained in order to obtain a sufficient ejection pressure. For this reason, a narrow portion (orifice) is usually provided between the ink pressure chamber and the ink supply path.

  On the other hand, when bubbles are generated in the ink pressure chamber during the ink discharge operation, the pressure for discharging the ink droplets is absorbed by the bubbles, resulting in discharge failure. For this reason, there is known a head in which bubbles are removed by circulating ink in an ink pressure chamber.

  However, if an orifice is provided in the ink supply path, it becomes difficult for the ink to flow, and bubbles are not sufficiently removed.

  Therefore, development of an ink jet recording head that can discharge ink droplets satisfactorily with a sufficient discharge pressure is desired.

An ink jet recording head according to an embodiment communicates with a first substrate having a plurality of ink pressure chambers extending in a first direction, a second substrate stacked on the first substrate, and each ink pressure chamber. A plurality of nozzles respectively provided in the center in the longitudinal direction of the ink pressure chamber, and a plurality of actuators that pressurize ink in each ink pressure chamber and eject ink droplets through the nozzles. The second substrate communicates with one end in the longitudinal direction of the plurality of ink pressure chambers and extends in a second direction intersecting the first direction, and communicates with the other end of the plurality of ink pressure chambers. And an ink discharge path extending in the second direction. The cross-sectional area of the connection portion between the ink pressure chamber and the ink supply path and the cross-sectional area of the connection portion between the ink pressure chamber and the ink discharge path are the cross-sectional areas in the direction crossing the longitudinal direction of the ink pressure chamber. More than half.

FIG. 1 is a partially enlarged cross-sectional view showing a main part of the ink jet recording head according to the first embodiment. FIG. 2 is a schematic perspective view showing a main part of the ink jet recording head of FIG. FIG. 3 is a plan view of the ink jet recording head of FIG. 1 as viewed from the direction in which the ink droplets protrude. 4 is a rear view of the drive substrate of the ink jet recording head of FIG. 3 as viewed from the supply substrate side. FIG. 5 is a schematic view showing a part of the ink flow path of the ink jet recording head of FIG. FIG. 6 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 7 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 8 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 9 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 10 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 11 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 12 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 13 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 14 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 15 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 16 is a partially enlarged cross-sectional view in which a main part of an ink jet recording head according to a modification of the first embodiment is partially enlarged. FIG. 17 is a partial enlarged cross-sectional view showing the main part of the ink jet recording head according to the second embodiment. FIG. 18 is a schematic perspective view showing a main part of the ink jet recording head of FIG. FIG. 19 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 20 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 21 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 22 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 23 is a cross-sectional view for explaining a method of manufacturing the ink jet recording head of FIG. FIG. 24 is a schematic diagram showing an ink jet recording system using the ink jet recording head of FIGS. 1, 16, and 17. FIG.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a partial enlarged cross-sectional view showing a main part of an ink jet recording head 100 (hereinafter simply referred to as the head 100) according to the first embodiment. FIG. 2 is a schematic perspective view showing the main part of the head 100. FIG. 3 is a plan view of the head 100 as viewed from the direction in which the ink droplets protrude. FIG. 4 is a rear view of the driving substrate 10 of the head 100 as viewed from the supply substrate 20 side. 2 and 3, the illustration of the insulating film 50 is omitted to make it easier to see the piezoelectric element 40 and its wiring structure.

  The head 100 of this embodiment is a piezoelectric MEMS ink jet recording head. The head 100 includes a drive substrate 10 (first substrate) formed of, for example, Si, a supply substrate 20 (second substrate) formed of, for example, Si, and a nozzle plate 30 (vibrating plate) formed of an Si oxide film (thermal oxide film). And a plurality of piezoelectric elements 40 (actuators). An insulating film 50 is provided on the surface 30 a of the nozzle plate 30 provided with a plurality of piezoelectric elements 40 on the side away from the drive substrate 10. A thermal oxide film 60 made of a Si oxide film is provided on the back surface of the supply substrate 20 on the side away from the drive substrate 10.

  The drive substrate 10 has a plurality of elongated ink pressure chambers 11 penetrating the substrate in communication with the first surface 10a (surface separated from the supply substrate 20) and the second surface 10b (surface on the supply substrate 20 side). The plurality of ink pressure chambers 11 extend in a first direction (hereinafter sometimes referred to as a longitudinal direction) along the surface direction of the drive substrate 10, and extend along a surface direction orthogonal to the first direction. Are arranged side by side in a second direction (hereinafter sometimes referred to as an arrangement direction).

  As shown in FIG. 4, the plurality of ink pressure chambers 11 are formed in, for example, four rows, and both ends in the longitudinal direction are aligned in the alignment direction. The length of each ink pressure chamber 11 is designed to be 600 μm or more, the width of each ink pressure chamber 11 is about 50 to 100 μm, and the pitch in the arrangement direction is about 60 to 150 μm. In the present embodiment, the cross-sectional shape of the ink pressure chamber 11 is oval.

  The drive substrate 10 has a thickness of 50 to 300 μm, for example, and preferably has a thickness of 30 to 200 μm. The thickness of the drive substrate 10 is a thickness that can provide sufficient rigidity to the partition walls between the ink pressure chambers 11 adjacent in the arrangement direction, and can increase the arrangement density of the ink pressure chambers 11 as much as possible. The ink pressure chamber 11 is designed to have a thickness that allows the volume of the ink pressure chamber 11 to be an appropriate value.

  The supply substrate 20 is bonded to the second surface 10 b of the drive substrate 10 with an adhesive 15, for example. The laminated body 70 in which the driving substrate 10 and the supply substrate 20 are stacked has a thickness of 500 μm or less and has flexibility. In this embodiment, the thickness of the drive substrate 10 is formed to about 100 μm, the thickness of the supply substrate 20 is formed to about 150 μm, and the thickness of the laminate 70 including the layer of the adhesive 15 is formed to about 260 μm.

  The supply substrate 20 includes a plurality (three in this embodiment) of ink supply paths 22 extending in the arrangement direction of the plurality of ink pressure chambers 11 and a plurality (two in this embodiment) extending in the arrangement direction. An ink discharge path 24 is provided. In FIG. 4, the positions of three ink supply paths 22 and two ink discharge paths 24 provided on a supply board 20 (not shown) facing the drive board 10 are indicated by broken lines.

  As shown in FIG. 4, the plurality of ink supply paths 22 and the plurality of ink discharge paths 24 are alternately provided along the first direction. The ink supply path 22 and the ink discharge path 24 are bottomed grooves formed on the surface 20 a of the supply substrate 20 on the drive substrate 10 side. The supply port 22 a of the ink supply path 22 is provided at the lower end of the ink supply path 22 in the figure, and the discharge port 24 a of the ink discharge path 24 is provided at the upper end of the ink discharge path 24 in the figure. The supply port 22a and the discharge port 24a are provided through the supply substrate 20, respectively.

  Of the three ink supply paths 22, the central ink supply path is arranged between the two central rows of ink pressure chambers 11 and functions as an ink supply path 22 common to the two rows of ink pressure chambers 11. Similarly, the two ink discharge paths 24 function as an ink discharge path common to two adjacent rows of ink pressure chambers 11. Thus, by providing the common ink supply path 22 and the ink discharge path 24 in the two rows of ink pressure chambers 11, the cross-sectional areas of the ink supply path 22 and the ink discharge path 24 are increased as compared with the case where they are provided individually. And the flow path resistance of the ink can be lowered.

  Each ink supply path 22 is formed at a position communicating with one end of the plurality of ink pressure chambers 11 arranged in the second direction, and each ink discharge path 24 is formed in the plurality of ink pressure chambers 11 arranged in the second direction. It is formed at a position communicating with the other end. In other words, the second surface 10 b side of each ink pressure chamber 11 is connected to the supply substrate 20 except that one end of the ink pressure chamber 11 communicates with the ink supply path 22 and the other end communicates with the ink discharge path 24. It is blocked by the surface 20a.

  The cross-sectional area of the connection portion between each ink pressure chamber 11 and the ink supply path 22 and the cross-sectional area of the connection portion between each ink pressure chamber 11 and the ink discharge path 24 are in the longitudinal direction of each ink pressure chamber 11. Designed to be more than half of the cross-sectional area in the direction perpendicular to. In the present embodiment, the cross-sectional area of the connection portion between the ink pressure chamber 11 and the ink supply path 22 and the cross-sectional area of the connection portion between the ink pressure chamber 11 and the ink discharge path 24 are represented by the ink pressure chamber 11. The cross-sectional area was designed to be substantially the same as the cross-sectional area in the direction orthogonal to the longitudinal direction.

  The nozzle plate 30 is provided so as to contact the first surface 10a of the drive substrate 10 on the side away from the supply substrate 20 and close the first surface 10a side of each ink pressure chamber 11. The nozzle plate 30 has a plurality of nozzles 32 communicating with each ink pressure chamber 11 at the center along the longitudinal direction of each ink pressure chamber 11. A plurality of nozzles 32 provided corresponding to each ink pressure chamber 11 penetrates the nozzle plate 30 and extends through a piezoelectric element 40 described later. That is, each ink pressure chamber 11 communicates with the outside of the head 100 via the nozzle 32. The distance from each nozzle 32 to both ends in the longitudinal direction of the corresponding ink pressure chamber 11 is designed to be 300 μm or more, and preferably 500 μm or more.

The nozzle plate 30 is formed of, for example, a Si oxide film (SiO ₂ ) having a thickness of about 1 to 5 μm, which is created by thermal oxidation or CVD. The Si oxide film is desirably amorphous from the viewpoint that uniform deformation can be realized. In addition, it is desirable to form the nozzle plate 30 with a Si oxide film from the viewpoint of easy manufacture of a film having a stable composition and characteristics. Furthermore, it is desirable to form the nozzle plate 30 with a Si oxide film from the viewpoint of good consistency with the conventional semiconductor process.

  The plurality of piezoelectric elements 40 are stacked on the surface 30a of the nozzle plate 30 so as to surround the plurality of nozzles 32, respectively. As shown in FIG. 1, each piezoelectric element 40 has a lower electrode 42 superimposed on the surface 30 a of the nozzle plate 30, a piezoelectric film 44 superimposed on the lower electrode 42, and an upper electrode 46 superimposed on the piezoelectric film 44. The length of each piezoelectric element 40 along the first direction is shorter than the length of the ink pressure chamber 11 along the first direction. The width along the second direction of each piezoelectric element 40 is shorter than the width along the second direction of the ink pressure chamber 11 described above.

  A part of the lower electrode 42 of each piezoelectric element 40 extends along the surface 30 a of the nozzle plate 30 and functions as the individual drive wiring 43. As shown in FIG. 3, an individual wiring pad 43 a is provided at the end of each individual drive wiring 43. An insulating film 50 is formed on the surface 30 a of the nozzle plate 30 including the surface of the piezoelectric element 40. A via hole 52 is formed in a part of the insulating film 50 in contact with the upper electrode 46, and a lead wiring 47 is drawn from the upper electrode 46 through the via hole 52. The lead-out wiring 47 extends on the insulating film 50 to the outside and is connected to the common wiring pad 47a. The insulating film 50 extends to a position that partially covers the inner surface of the nozzle 32.

A piezoelectric material having a large electrostriction constant such as lead zirconate titanate (Pb (Zr, Ti) O ₃ , PZT) is suitable for the piezoelectric film 44 of each piezoelectric element 40. When PZT is used for the piezoelectric film 44, a noble metal such as Pt, Au, or Ir or a conductive oxide such as SrRuO ₃ is suitable for the lower electrode 42 and the upper electrode 46. In addition, a piezoelectric material suitable for a silicon process such as AlN or ZrO ₂ can be used as the piezoelectric film 44. In this case, general electrode materials and wiring materials such as Al and Cu can be used as the lower electrode 42 and the upper electrode 46.

Hereinafter, the operation of the head 100 described above will be described.
First, ink is supplied from an external ink supply pump (not shown) to the plurality of ink pressure chambers 11 in each row via the three ink supply paths 22, and the two ink discharge paths 24 are supplied by an external ink discharge pump (not shown). Ink is discharged from the plurality of ink pressure chambers 11 in each row. Thereby, the ink circulates in the plurality of ink pressure chambers 11. At this time, bubbles and the like generated in each ink pressure chamber 11 are also quickly discharged out of the ink pressure chamber 11.

  As described above, in a state where ink is circulated in each ink pressure chamber 11, a drive voltage is selected between the lower electrode 42 and the upper electrode 46 of each piezoelectric element 40 in accordance with a recording signal from an external drive circuit (not shown). Apply the power. As a result, the piezoelectric film 44 of the piezoelectric element 40 to which the drive voltage is applied contracts and the piezoelectric element 40 is bent and deformed into a concave shape, the volume of the corresponding ink pressure chamber 11 is increased, and the ink supply path 22 to the ink pressure chamber 11 is increased. Ink flows in through. Next, when the drive voltage is removed, the bending deformation of the piezoelectric element 40 is restored, the volume of the ink pressure chamber 11 is reduced, the pressure in the ink pressure chamber 11 is increased, and ink droplets are ejected through the nozzles 32. To do.

  In order to eject ink droplets satisfactorily at a sufficient ejection pressure, it is necessary to maintain the pressure of the ink in the ink pressure chamber 11 at a certain level or higher when ejecting ink droplets. For this reason, in this embodiment, the length of the ink pressure chamber 11 along the first direction is made sufficiently long so that both ends of the ink pressure chamber 11 from the nozzle 32 in the longitudinal direction (the ink supply path 22 or the ink discharge path). 24) is made sufficiently long to generate an inertial resistance due to the inertial mass of the ink, thereby suppressing the pressure from escaping from the ink pressure chamber 11 to the ink supply path 22 and the ink discharge path 24. .

  In other words, the length of the ink pressure chamber 11 is designed in the head 100 of the present embodiment to such an extent that a sufficient discharge pressure can be obtained for bending and deforming the piezoelectric element 40 to discharge ink droplets. Specifically, a vibration wave (hereinafter referred to as a pressure wave) based on a change in ink pressure during ink droplet ejection is sufficiently attenuated at both ends in the longitudinal direction of the ink pressure chamber 11, and the ink supply path 22 and the ink discharge. The length of the ink pressure chamber 11 was designed so that vibration was hardly transmitted to the path 24.

  FIG. 5 is a schematic view showing a part of the ink flow path (ink pressure chamber 11, ink supply path 22, ink discharge path 24) in the head 100 of the present embodiment. Hereinafter, with reference to FIG. 5, how the pressure wave is transmitted during ink droplet ejection will be described. Here, paying attention to one ink pressure chamber 111, how to transmit a pressure wave when an ink droplet is ejected from the nozzle 32 of the ink pressure chamber 111 will be described.

  When ejecting ink droplets, the ink pressure chamber 111 expands and contracts. At this time, the ink is vibrated by the ink meniscus of the nozzle 32 due to the ejection of the ink droplets. This vibration is transmitted through the ink flow path as a pressure wave. That is, the pressure wave generated in the vicinity of the nozzle 32 is transmitted through the ink toward both ends in the longitudinal direction of the ink pressure chamber 111, is transmitted to the ink supply path 22 and the ink discharge path 24, and is adjacent to the other ink pressure chamber 112. , 113.

  At this time, the pressure wave generated in the vicinity of the nozzle 32 travels in the ink pressure chamber 111 having a sufficient length toward one end in the longitudinal direction (the right end in the figure) and gradually attenuates due to the inertial resistance of the ink. To do. Further, the pressure wave propagates to the ink supply path 22 provided in a different manner from the ink pressure chamber 111. At this time, a part of the pressure wave is reflected and attenuated at one end of the ink pressure chamber 111. Furthermore, even when a pressure wave enters the adjacent ink pressure chamber 112 via the ink supply path 22, a part of the pressure wave is reflected by the wall of the flow path and attenuates. That is, according to the present embodiment, the pressure wave propagation path is bent a total of four times, and the pressure wave is attenuated each time, so that the pressure wave generated in the ink pressure chamber 111 is propagated to the adjacent ink pressure chamber 112. Absent.

  Similarly, the pressure wave propagating from the vicinity of the nozzle 32 toward the other end (the left end in the drawing) of the ink pressure chamber 111 is bent and propagated four times before reaching the adjacent ink pressure chamber 113, and therefore the pressure wave is propagated. It does not sufficiently attenuate and propagate to the adjacent ink pressure chamber 113. In other words, in this embodiment, the pressure wave generated in the ink pressure chamber 111 propagates to the adjacent ink pressure chambers 112 and 113 and adversely affects the ink droplet ejection operation in the adjacent ink pressure chambers 112 and 113. The length of the ink pressure chamber 111 was designed so as not to exist.

  As described above, according to the head 100 of the present embodiment, the ink pressure chamber 11 is secured on the supply substrate 20 stacked on the drive substrate 10 on which the ink pressure chamber 11 is formed, and the ink pressure chamber 11 is sufficiently long. By forming the ink supply path 22 and the ink discharge path 24 orthogonal to each other, a sufficient pressure for ink ejection can be secured in the ink pressure chamber 11, and there is a problem of interference with the adjacent ink pressure chamber 11. Can also be eliminated. That is, the head 100 of this embodiment can discharge ink droplets satisfactorily with a sufficient discharge pressure.

Next, a method for manufacturing the head 100 described above will be described with reference to FIGS.
First, as shown in FIG. 6, the drive substrate 10 is oxidized by thermal oxidation to form a nozzle plate 30 made of a Si oxide film. In this embodiment, the nozzle plate 30 is formed by thermal oxidation of the Si substrate, but plasma CVD methods other than the thermal oxidation method, CVD methods using TEOS as a raw material, and the like can also be used.

  Thereafter, as shown in FIG. 6, a layer of the lower electrode 42 made of Ti / Pt is formed on the nozzle plate 30 by sputtering, and a layer of the piezoelectric film 44 made of PZT is formed thereon, and further thereon Then, a layer of the upper electrode 46 made of Au is formed.

  Next, as shown in FIG. 7, the upper electrode 46, the piezoelectric film 44, and the lower electrode 42 are sequentially etched and patterned by photolithography and wet etching to form a plurality of piezoelectric elements 40, a plurality of nozzles 32, and a plurality of Individual drive wirings 43 are formed.

  Next, as shown in FIG. 8, an insulating film 50 is formed over the entire top of the nozzle plate 30 and the plurality of piezoelectric elements 40, and patterned by photolithography and reactive ion etching. A via hole 81 is formed.

  Next, as shown in FIG. 9, patterning is performed by sputtering film formation, photolithography, and reactive ion etching to form contact portions 82 with the upper electrodes 46 in the respective via holes 81 and connect to the respective contact portions 82. A plurality of lead wires 47 are formed.

  Next, as shown in FIG. 10, the first temporary fixing substrate 84 is fixed on the insulating film 50 via the temporary fixing adhesive 83. Further, the drive substrate 10 is processed by grinding and CMP from the second surface 10b side to be thinned.

  Next, as shown in FIG. 11, a plurality of ink pressure chambers 11 are formed from the second surface 10b side of the drive substrate 10 by back surface photolithography and deep etching (D-RIE). At this time, etching and passivation of the driving substrate 10 are repeated several times to form a plurality of ink pressure chambers 11 having a desired depth.

  Next, as shown in FIG. 12, a supply substrate 20 having Si oxide films 20 ′ and 60 formed on both sides is prepared, and the first surface (the upper surface in the drawing) is provided with a temporary fixing adhesive 85 therebetween. Second temporary fixing substrate 86 is bonded.

  Next, as shown in FIG. 13, the supply substrate 20 is processed by grinding and CMP from the other surface (the lower surface in the drawing) side of the supply substrate 20, and the supply substrate 20 is thinned. Further, by backside photolithography and D-RIE A plurality of ink supply paths 22 and a plurality of ink discharge paths 24 are formed.

  Next, the supply substrate 20 shown in FIG. 13 is turned upside down, and the drive substrate 10 shown in FIG. 11 is overlaid, and the second surface 10b of the drive substrate 10 and the surface of the supply substrate 20 are bonded to each other as shown in FIG. Adhere by 15. Thereby, one end of each ink pressure chamber 11 of the drive substrate 10 communicates with the ink supply path 22 of the supply substrate 20, and the other end of each ink pressure chamber 11 of the drive substrate 10 communicates with the ink discharge path 24 of the supply substrate 20. Is done.

  Further, as shown in FIG. 15, the first temporary fixing substrate 84 and the second temporary fixing substrate 86 are peeled off. As a peeling method, an organic solvent that does not dissolve the adhesive 15 but dissolves only the temporary fixing adhesives 83 and 85 may be used, or peeling by heating, mechanical peeling, or the like may be used.

  In the series of film formation and etching described above, a large number of chips are simultaneously formed on a single wafer, and are divided into individual chips after the process is completed.

  As described above, according to the method for manufacturing the head 100 of the present embodiment, the head 100 can be manufactured by a simple process, and is particularly excellent in long-term withstand voltage and high drive durability and reliability. In addition, it is possible to provide the piezoelectric MEMS ink jet recording head 100 having high driving efficiency.

  According to the present embodiment, since the plurality of ink pressure chambers 11 are extended in the surface direction of the drive substrate 10, the etching depth of the drive substrate 10 can be reduced, and the manufacturing cost of the head 100 is reduced accordingly. Can do. The same effect can be obtained by lengthening the ink pressure chamber 11 in the thickness direction of the drive substrate 10, but the number of times of passivation and D-RIE increases correspondingly, and the manufacturing cost increases.

  In addition, according to the present embodiment, since the plurality of ink pressure chambers 11 are extended in the surface direction of the drive substrate 10, the drive substrate 10 can be thinned, and the flexible head 100 can be provided.

(Modification of the first embodiment)
FIG. 16 is a partial enlarged cross-sectional view showing an ink jet recording head 120 (hereinafter simply referred to as the head 120) according to a modification of the first embodiment. The head 120 has a template side wall 122 at a part of the side wall of the ink pressure chamber 11, and has a nozzle extension 124 that extends the nozzle 32 toward the ink pressure chamber 11. The rest is the same as the head 100 of the first embodiment. Therefore, about the content which overlaps with 1st Embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  The template side wall 122 and the nozzle extension 124 are formed of a Si oxide film. In this modification, both the template side wall 122 and the nozzle extension 124 are formed at the same time as the nozzle plate 30 is formed by thermal oxidation. The template side wall 122 is provided along the outer periphery of the ink pressure chamber 11 and defines the shape of the ink pressure chamber 11. The nozzle extension 124 has a cylindrical shape having the same inner diameter as that of the nozzle 32, and extends the nozzle 32 toward the ink pressure chamber 11.

  The template side wall 122 serves as an etching stopper when the ink pressure chamber 11 is formed by D-RIE. That is, when the ink pressure chamber 11 is formed by etching from the second surface 10b side of the driving substrate 10, the template side wall 122 prevents further etching. For this reason, by providing the template side wall 122, the shape accuracy of the ink pressure chamber 11 can be significantly increased.

  Further, the nozzle extension 124 improves the accuracy of the ejection angle when ejecting ink droplets, and enables gradation control of the ejection amount of ink droplets. When the nozzle extension portion 124 is provided to increase the total length of the nozzle 32, the amount of ink droplets to be ejected can be dynamically changed, and the problem of bubbles entering the ink pressure chamber 11 through the nozzles 32 during ejection can be suppressed. .

(Second Embodiment)
FIG. 17 is a partially enlarged cross-sectional view in which a main part of an ink jet recording head 200 (hereinafter simply referred to as the head 200) according to the second embodiment is partially enlarged. FIG. 18 is a partially enlarged perspective view showing a part of the head 200 of FIG.

  The head 200 of this embodiment has substantially the same structure as the head 100 of the first embodiment described above, except that the supply substrate 220 and the support substrate 230 are provided instead of the supply substrate 20. Therefore, here, a configuration different from the first embodiment will be described, and a configuration that functions in the same manner as the first embodiment will be denoted by the same reference numeral, and a detailed description thereof will be omitted. In particular, the description of the structure of the driving substrate 10 and the manufacturing method thereof is omitted here.

  The supply substrate 220 is made of, for example, Si, and is bonded and fixed to the second surface 10 b of the drive substrate 10 via the adhesive 15. The support substrate 230 is bonded and fixed to the thermal oxide film 60 separated from the drive substrate 10 of the supply substrate 220 via an adhesive 210. The support substrate 230 is formed in a flat plate shape by, for example, Si.

  The supply substrate 220 has a plurality (three in this embodiment) of ink supply paths 222 and a plurality (two in the present embodiment) of ink discharge paths 224. Each ink supply path 222 extends in a second direction orthogonal to the first direction at a position facing and spaced from one end of the ink pressure chambers 11 of each row of the drive substrate 10, and each ink discharge path 224 is The ink pressure chambers 11 in each row extend in the second direction at positions facing and spaced from the other ends of the ink pressure chambers 11. The plurality of ink supply paths 222 and the plurality of ink discharge paths 224 are each open to the support substrate 230 side, and one surface side is blocked by the support substrate 230.

  Further, the supply substrate 220 has a plurality of communication passages 223 having a substantially circular cross section that communicates one end of each ink pressure chamber 11 and the ink supply passage 222, and a substantial communication that communicates the other end of each ink pressure chamber 11 and the ink discharge passage 224. A plurality of communication passages 225 having a circular cross section are provided. In the present embodiment, the individual communication passages 223 and 225 are provided corresponding to the respective ink pressure chambers 11, but elongated and long common communication passages 223 and 225 extending in the second direction may be formed. Further, the cross-sectional shape of the communication passages 223 and 225 is not limited to a circle and may be a rectangle or the like. In any case, the cross-sectional area of the communication passages 223 and 225 communicating with each ink pressure chamber 11 is more than half of the cross-sectional area in the direction orthogonal to the longitudinal direction of the ink pressure chamber 11.

  As described above, the head 200 of this embodiment includes the communication path 223 between one end of the ink pressure chamber 11 that is linearly extended and the ink supply path 222, and the other end of the ink pressure chamber 11 and the ink discharge path 224. Since the communication path 225 is provided between the ink supply path 222 and the ink discharge path 224, the inertial resistance due to the inertial mass of the ink can be sufficiently exerted in each ink pressure chamber 11 regardless of the shape and position of the ink supply path 222 and the ink discharge path 224. Drops can be discharged well.

  Further, according to the present embodiment, the layout of the ink supply path 222 and the ink discharge path 224 can be freely set, and the cross-sectional areas of the ink supply path 222 and the ink discharge path 224 can be increased to some extent. The ink flow path resistance in the ink discharge path 224 can be reduced, the ink can be circulated well in each ink pressure chamber 11, and bubbles can be removed.

  Hereinafter, a method for manufacturing the head 200 according to the second embodiment will be described with reference to FIGS. As described above, the description of the method for manufacturing the drive substrate 10 is omitted here.

  First, as shown in FIG. 19, a supply substrate 220 having Si oxide films 220 ′ formed on both sides is prepared, and from one surface (the lower surface in the drawing) side of the supply substrate 220, photolithography and D-RIE are performed. The ink supply path 222 and the ink discharge path 224 described above are formed.

  Next, as shown in FIG. 20, the support substrate 230 is bonded and fixed to the one surface of the supply substrate 220 on which the ink supply path 222 and the ink discharge path 224 are formed via an adhesive 210. The support substrate 230 is provided in advance with a plurality of supply ports (not shown) communicating with the ink supply paths 222 and with a plurality of discharge ports (not shown) communicating with the ink discharge paths 224.

  Next, as shown in FIG. 21, from the other surface (upper surface in the drawing) side of the supply substrate 220, the supply substrate 220 is thinned by grinding and CMP, and further, back surface photolithography and D-RIE are performed. The plurality of communication paths 223 and the plurality of communication paths 225 described above are formed.

  Next, as shown in FIG. 22, a plurality of ink pressure chambers 11 are formed in advance on the surface of the supply substrate 220 away from the support substrate 230 via the adhesive 15, and the nozzle plate 30 and the plurality of piezoelectric elements 40. The second surface 10b of the drive substrate 10 provided with (manufactured by the manufacturing steps of FIGS. 6 to 11) is bonded and fixed. As a result, one end of each ink pressure chamber 11 of the drive substrate 10 communicates with the communication path 223 of the supply substrate 220, and the other end of each ink pressure chamber 11 of the drive substrate 10 communicates with the communication path 225 of the supply substrate 220. .

  Further, as shown in FIG. 23, the first temporary fixing substrate 84 on the drive substrate 10 side is peeled off. As a peeling method, an organic solvent that does not dissolve the adhesive 15 but dissolves only the temporary fixing adhesive 83 may be used, or peeling by heating, mechanical peeling, or the like may be used.

  In the series of film formation and etching described above, a large number of chips are simultaneously formed on a single wafer, and are divided into individual chips after the process is completed.

  As described above, according to the head 200 of the present embodiment, it can be manufactured by a simple process, and the same effects as those of the head 100 of the first embodiment described above can be achieved. In particular, according to the present embodiment, it is possible to provide the piezoelectric MEMS type ink jet recording head 200 having the ink supply path 222 and the ink discharge path 224 having a large cross-sectional area and a low flow path resistance.

(Example of use)
Since the ink jet recording heads 100, 120, and 200 according to the above-described embodiments can be thinned by about several hundreds of micrometers, as shown in FIG. Simply referred to as system 300).

  The system 300 includes a plurality of (three in this embodiment) linear actuators 320 for bending the head 100 (which will be described as a representative) as shown in the figure. The linear actuator 320 is, for example, a solenoid. Each linear actuator 320 is a mechanism that can move in a direction perpendicular to the substrate surface of the head 100.

  The head 100 is connected to an ink supply pipe 330 and an ink discharge pipe 340 which are formed of a tube that can be bent flexibly. The ink supply pipe 330 is connected to the plurality of ink supply paths 22 of the head 100, and the ink discharge pipe 340 is connected to the plurality of ink discharge paths 24.

  Since the head 100 can be flexibly bent by the system 300, the head 100 can be bent by the linear actuator 320 along the printed curved surface of the non-printed material 350, and the distance between the non-printed material 350 and the head 100 can be kept constant over a wide range. It becomes possible to do. Therefore, it is possible to print a wide range in one pass on the non-printed material 350 having a curved surface.

  The embodiments of the present invention have been described above with reference to specific examples. The above embodiment is merely given as an example and does not limit the present invention. In the description of the embodiment, the description of the ink jet recording head and its manufacturing method, etc., which are not directly necessary for the description of the present invention is omitted, but the ink jet recording head and the manufacturing thereof are required. Elements related to the method and the like can be appropriately selected and used.

In addition, all inkjet recording heads that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention. The scope of the present invention is defined by the appended claims and equivalents thereof.
Hereinafter, the invention described in the scope of claims at the beginning of the application of the present application will be added.
[1]
A first substrate having a plurality of ink pressure chambers extending in a first direction;
An ink supply path that is stacked on the first substrate, communicates with one end in the longitudinal direction of the plurality of ink pressure chambers, and extends in a second direction that intersects the first direction; and the plurality of ink pressures A second substrate having an ink discharge path communicating with the other end of the chamber and extending in the second direction;
A plurality of nozzles provided in the center of the ink pressure chamber in the longitudinal direction in communication with the ink pressure chambers;
A plurality of actuators that pressurize ink in each ink pressure chamber and eject ink droplets through the nozzles;
An ink jet recording head.
[2]
The distance from the nozzle to both ends in the longitudinal direction of the ink pressure chamber is 300 μm or more, respectively.
[1] Inkjet recording head.
[3]
The cross-sectional area of the connection portion between the ink pressure chamber and the ink supply path and the cross-sectional area of the connection portion between the ink pressure chamber and the ink discharge path intersect with the longitudinal direction of the ink pressure chamber. More than half of the cross-sectional area in the direction,
[1] Inkjet recording head.
[4]
The thickness of the laminate of the first substrate and the second substrate is 300 μm or less, and the laminate has flexibility.
[1] Inkjet recording head.
[5]
A vibration plate provided on a surface of the first substrate spaced apart from the second substrate and having the nozzle and formed of a thermal oxide film;
A thermal oxide film provided on a surface of the second substrate spaced apart from the first substrate,
[4] Inkjet recording head.

  DESCRIPTION OF SYMBOLS 10 ... Drive board, 11 ... Ink pressure chamber, 20, 220 ... Supply board, 22, 222 ... Ink supply path, 24, 224 ... Ink discharge path, 30 ... Nozzle plate, 32 ... Nozzle, 40 ... Piezoelectric element, 50 ... Insulating film, 60 ... Thermal oxide film, 100, 120, 200 ... Inkjet recording head, 122 ... Template side wall, 124 ... Nozzle extension, 223, 225 ... Communication path, 230 ... Support substrate, 300 ... Inkjet recording system, 320 ... Linear actuator, 330 ... Ink supply pipe, 340 ... Ink discharge pipe, 350 ... Non-printed material.

Claims (5)

A first substrate having a plurality of ink pressure chambers extending in a first direction;
An ink supply path that is stacked on the first substrate, communicates with one end in the longitudinal direction of the plurality of ink pressure chambers, and extends in a second direction that intersects the first direction; and the plurality of ink pressures A second substrate having an ink discharge path communicating with the other end of the chamber and extending in the second direction;
A plurality of nozzles provided in the center of the ink pressure chamber in the longitudinal direction in communication with the ink pressure chambers;
Pressurizing the ink in the ink pressure chamber have a, a plurality of actuators for ejecting ink droplets through said nozzle,
The cross-sectional area of the connection portion between the ink pressure chamber and the ink supply path and the cross-sectional area of the connection portion between the ink pressure chamber and the ink discharge path intersect with the longitudinal direction of the ink pressure chamber. An ink jet recording head that is more than half of the sectional area in the direction . The distance from the nozzle to both ends in the longitudinal direction of the ink pressure chamber is 300 μm or more, respectively.
The ink jet recording head according to claim 1. The thickness of the laminate of the first substrate and the second substrate is 300 μm or less, and the laminate has flexibility.
The ink jet recording head according to claim 1. A diaphragm provided on a surface of the first substrate spaced apart from the second substrate, the diaphragm having the nozzle and formed of a thermal oxide film;
A thermal oxide film provided on a surface of the second substrate spaced apart from the first substrate,
The ink jet recording head according to claim 3 .   A first substrate having a plurality of ink pressure chambers extending in a first direction;
  It is laminated on the first substrate, has a back surface separated from the first substrate, communicates with one end in the longitudinal direction of the plurality of ink pressure chambers, and extends in a second direction intersecting the first direction. A second substrate having an ink supply path that opens to the back surface, and an ink discharge path that communicates with the other ends of the plurality of ink pressure chambers and extends in the second direction and opens to the back surface;
  A third substrate laminated on the back surface of the second substrate and blocking the opening of the ink supply path and the opening of the ink discharge path;
  A plurality of nozzles provided in the center of the ink pressure chamber in the longitudinal direction in communication with the ink pressure chambers;
  A plurality of actuators that pressurize ink in each of the ink pressure chambers and eject ink droplets through the nozzles;
  The cross-sectional area of the connection portion between the ink pressure chamber and the ink supply path and the cross-sectional area of the connection portion between the ink pressure chamber and the ink discharge path intersect with the longitudinal direction of the ink pressure chamber. An ink jet recording head that is more than half of the sectional area in the direction.