JP6651751B2 - Manufacturing method of liquid ejection device and liquid ejection device - Google Patents

Description

The present invention relates to a method for manufacturing a liquid ejection device and a liquid ejection device .

  Patent Document 1 discloses an ink jet head that discharges ink from nozzles as a liquid discharge device. The ink jet head includes a flow path forming substrate made of silicon, a plurality of piezoelectric elements provided in the flow path forming substrate corresponding to the plurality of pressure chambers, and a flow path forming substrate covering the plurality of piezoelectric elements. And a reservoir forming substrate joined to the substrate. A manifold (communication portion) extending in the direction in which the plurality of pressure chambers are arranged and communicating with the plurality of pressure chambers is formed on the flow path forming substrate. On the other hand, a reservoir portion connected to the manifold is formed on the reservoir forming substrate.

  The manufacture of the ink jet head of Patent Document 1 is performed as follows. First, a diaphragm made of silicon dioxide and zirconium oxide is formed on the surface of a silicon channel forming substrate. Next, a plurality of piezoelectric elements corresponding to the plurality of pressure chambers are formed on the vibration plate. After the formation of the plurality of piezoelectric elements, a part of the vibration plate is removed by etching to form a part (diaphragm removal part) that allows the manifold to communicate with the reservoir part. Further, an insulating film of silicon nitride is formed on the diaphragm, and a through hole having a smaller opening area than the diaphragm removing portion is formed in a region of the insulating film corresponding to the diaphragm removing portion. .

  Next, after forming an adhesion layer and a metal layer over the entire surface of the vibration plate, a lead electrode corresponding to the piezoelectric element is formed by patterning the adhesion layer and the metal layer. At the time of the above-mentioned patterning, the adhesion layer and the metal layer covering the vibration plate removing portion are left without being removed, and the through-hole of the insulating film is sealed by the adhesion layer and the metal layer. After forming the lead electrodes, the reservoir forming substrate is joined to the flow path forming substrate via the adhesion layer and the metal layer.

  Next, a plurality of pressure chambers and a manifold are formed on the flow path forming substrate by wet etching from the side opposite to the vibration plate. At this time, since the vibration plate removing portion and the through hole of the insulating film are closed by the adhesion layer and the metal layer, leakage of the etching solution to the reservoir forming substrate side is prevented. That is, the adhesion layer and the metal layer covering the diaphragm removal portion function as an etching stop film. After the plurality of pressure chambers and the manifold are formed by wet etching, the adhesion layer and the metal layer closing the manifold are removed by wet etching from the flow path forming substrate side.

  Patent Literature 2 discloses an ink jet head including the same flow path forming substrate and reservoir forming substrate as in Patent Literature 1. However, the manufacturing process of the inkjet head of Patent Document 2 differs from that of Patent Document 1 in the following.

  In Patent Literature 2, first, a vibration plate is formed on the surface of a flow path forming substrate, and an opening is formed in the vibration plate to allow the reservoir section and the manifold to communicate with each other. Next, a boron-doped layer is formed by diffusing boron in a region of the flow path forming substrate exposed from the opening of the diaphragm. Next, after joining the reservoir forming substrate to the diaphragm of the flow path forming substrate, a plurality of pressure chambers and manifolds are formed in the flow path forming substrate by wet etching from the side opposite to the diaphragm. At that time, the boron-doped layer functions as an etching stop film, and leakage of the etching solution to the reservoir forming substrate side is prevented. After forming the plurality of pressure chambers and the manifold by wet etching, the boron doped layer is removed by dry etching.

JP 2006-44083 A JP 2005-219243 A

  In Patent Literature 1, an etching stop film including an adhesive layer and a metal layer is formed in an opening (a portion where a diaphragm is removed) of a diaphragm. After the pressure chamber and the manifold are formed on the flow path forming substrate by wet etching, the etching stop film is removed by wet etching. Here, it is difficult to perform high-precision pattern control in wet etching, and in general, precise processing is difficult. However, in Patent Literature 1, the etching stop film is provided at a communicating portion between the manifold having a large area and the reservoir portion, and so high shape accuracy is not required. For this reason, when the etching stop film is removed by wet etching, even if the accuracy of the shape of the communicating portion is slightly deteriorated, no serious problem occurs.

  However, in a head that adopts a configuration in which ink is supplied from a reservoir forming substrate to a plurality of pressure chambers through individual liquid supply channels, poor processing accuracy of the wet etching described above poses a problem.

  In the head having the above configuration, the diaphragm has a plurality of individual holes for supplying the liquid to the plurality of pressure chambers, respectively. Is considerably smaller than that of the communicating part (for example, 50 μm or less). It is not preferable to remove the etching stop film covering such small individual holes by wet etching with low processing accuracy. That is, not only the film portion covering the individual hole but also the peripheral portion of the individual hole is removed, so that the sealing property between the flow path forming substrate and the reservoir forming substrate is deteriorated, and there is a possibility that a leak may occur. . Further, the degree of removal of the film covering the individual holes differs between the plurality of pressure chambers, and there is a problem that the flow path resistance of the individual holes varies among the plurality of pressure chambers.

  On the other hand, in Patent Literature 2, boron is diffused in a region of a flow path forming substrate exposed from an opening of a diaphragm to form a boron doped layer. Then, after the pressure chamber and the manifold are formed by wet etching, the boron doped layer is removed by dry etching. Dry etching allows more precise control of the shape pattern than wet etching, and thus does not easily cause the above-described problems. However, the above-mentioned boron-doped layer is formed only in a region exposed from the diaphragm in the opening, because it is formed by boron diffusion from the opening. That is, the diaphragm and the boron-doped layer hardly overlap. Therefore, when a pressure chamber or a manifold is formed by wet etching on the flow path forming substrate, when an external force acts on the boron dope layer by applying a liquid pressure of an etchant, the boron dope layer is damaged and an etching stop is caused. Function may be lost.

  An object of the present invention is to reliably prevent leakage of an etchant from a liquid supply hole connected to a pressure chamber when a pressure chamber is formed on a substrate by wet etching. Another object of the present invention is to precisely remove the sealing film covering the hole after forming the pressure chamber.

  According to a first aspect of the invention, there is provided a liquid ejecting apparatus manufacturing method, wherein an insulating film is formed on a surface of a substrate, and a part of the insulating film is removed by etching to form a through hole in the insulating film. Forming a through-hole forming step, forming a sealing film covering the insulating film and the through-hole, and forming a sealing film covering the through-hole; A pressure chamber for forming a pressure chamber in the substrate by wet bonding from a surface of the substrate opposite to a surface on which the insulating film is formed, at a position overlapping with the through hole of the substrate, A forming film removing step of removing a portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to a surface on which the insulating film is formed, It is characterized by having.

  In the present invention, first, an insulating film is formed on a substrate, and a through hole is formed in the insulating film. Next, a sealing film is formed to cover the insulating film and the through hole. In the present invention, the term “depositing a film” refers to attaching or depositing a film constituent material over a wide area of the surface of a target substrate by a known method such as sputtering or CVD, thereby forming a thin film on the substrate. To form. The formed sealing film seals the through hole and is formed continuously from the through hole to the outside. That is, the sealing film is arranged to overlap with a region of the insulating film outside the through hole with a sufficient area.

  Next, after joining the flow path member to the substrate, a pressure chamber is formed at a position overlapping the through hole of the substrate by wet etching from the opposite side to the insulating film. At this time, since the through holes of the insulating film are sealed with the sealing film, the etchant is prevented from leaking to the flow path member side. Further, since the sealing film overlaps with a region outside the through hole with a sufficient area, the sealing film is not easily damaged even when an external force such as a liquid pressure acts on the sealing film. After the pressure chamber is formed in the substrate by wet etching, the sealing film covering the through hole is removed by dry etching, so that the sealing film can be removed with high accuracy.

  In the method for manufacturing a liquid discharge device according to a second aspect, in the first aspect, in the sealing film forming step, etching resistance to dry etching in the sealing film removing step is equal to etching resistance of the insulating film. The sealing film is formed of a lower material.

  The sealing film is formed of a material having lower etching resistance to dry etching than the insulating film, that is, a material that is easily removed by dry etching. Therefore, the sealing film is promptly removed by dry etching, while the insulating film is not easily removed by etching.

  A method for manufacturing a liquid ejection apparatus according to a third aspect is the method according to the second aspect, further comprising: a piezoelectric element forming step of forming a piezoelectric element on the insulating film; It is characterized in that a film is formed.

  In the present invention, after forming a piezoelectric element on an insulating film, a sealing film is formed by film formation. When forming the piezoelectric element, high-temperature heat acts on the substrate. However, by forming the sealing film after the formation of the piezoelectric element, the influence of thermal stress or the like on the sealing film can be suppressed.

  A method for manufacturing a liquid ejection apparatus according to a fourth aspect is the method according to the third aspect, further comprising a wiring forming step of forming a wiring connected to the piezoelectric element on the insulating film. And forming a wiring protection film by forming the sealing film so as to cover the wiring.

  In the present invention, the number of steps can be reduced because the sealing film and the wiring protection film covering the wiring are formed by the same process.

  In any of the second to fourth inventions described above, the insulating film is preferably formed of silicon dioxide, and the sealing film is preferably formed of silicon nitride (fifth invention).

  According to a sixth aspect of the present invention, in the method for manufacturing a liquid ejection device according to the first aspect, the sealing film is formed to be thinner than the insulating film in the sealing film forming step. is there.

  Since the sealing film is thinner than the insulating film, the sealing film can be promptly removed by dry etching, and it is possible to prevent the insulating film from being scraped.

  A method for manufacturing a liquid ejection apparatus according to a seventh aspect is the method according to the sixth aspect, further comprising a piezoelectric element forming step of forming a piezoelectric element on the insulating film, wherein the sealing is performed after the piezoelectric element forming step. It is characterized in that a film is formed.

  In the present invention, after forming a piezoelectric element on an insulating film, a sealing film is formed by film formation.

  The manufacturing method of a liquid ejection device according to an eighth aspect is the method according to the seventh aspect, wherein the sealing film is formed so as to cover a piezoelectric film of the piezoelectric element in the sealing film forming step. And forming a piezoelectric film protection portion.

  In the present invention, the number of steps can be reduced because the sealing film and the piezoelectric film protection unit that covers the piezoelectric film of the piezoelectric element are formed by the same process.

  In any of the sixth to eighth inventions described above, the insulating film is preferably formed of silicon dioxide, and the sealing film is preferably formed of aluminum oxide (a ninth invention).

  According to a tenth aspect of the present invention, in the method of any of the sixth to ninth aspects, at least a part of a region covering the through hole on the sealing film includes the sealing film. A thick film forming step of forming a thick thick film; and a thick film removing step of removing the thick film after the pressure chamber forming step.

  When the sealing film is thin, it is easily damaged when liquid pressure acts on a portion of the sealing film that covers the through hole during wet etching of the pressure chamber. In the present invention, a thick film is formed in a portion of the sealing film that covers the through hole, and the sealing film is reinforced. Therefore, the sealing film is less likely to be damaged.

  In the tenth aspect, the thick film may be formed of a resin material (an eleventh aspect). Further, the thick film may be formed of an adhesive for bonding the substrate and the flow path member in the bonding step (a twelfth invention).

  A method of manufacturing a liquid ejection device according to a thirteenth aspect is characterized in that, in any one of the first to twelfth aspects, the diameter of the through hole is 50 μm or less.

  If the diameter of the through hole is as small as 50 μm or less, problems such as variations in flow path resistance caused by low etching accuracy cannot be ignored. Therefore, it is particularly effective to remove the sealing film by dry etching which enables high-definition processing.

FIG. 2 is a schematic plan view of the printer according to the embodiment. It is a top view of a head unit. FIG. 3 is a sectional view taken along line III-III of FIG. 2. It is a figure which shows the manufacturing process of a head unit, (a) vibration film formation, (b) common electrode film formation, (c) piezoelectric material film formation, (d) individual electrode film formation, (e) (F) shows piezoelectric patterning, and (g) shows common electrode patterning. 5A and 5B are diagrams illustrating a manufacturing process of a head unit, in which FIG. 5A illustrates the formation of a piezoelectric protective film, FIG. 5B illustrates the patterning of the piezoelectric protective film, FIG. 5C illustrates the formation of an interlayer insulating film, and FIG. (E) shows the formation of a through hole in the vibration film, (f) shows the formation of a wiring protection film (sealing film), and (g) shows the patterning of the interlayer insulating film and the wiring protection film. It is a figure which shows the manufacturing process of a head unit, (a) shows adhesion | attachment of a reservoir formation member, (b) shows a pressure chamber formation, (c) shows sealing film removal. It is a figure which shows the manufacturing process of the head unit of a modified form, (a) is a through-hole formation of a vibration film, (b) is a film formation of a piezoelectric protective film, (c) is a film formation of an interlayer insulating film, (d) () Shows the formation of the wiring, (e) shows the formation of the wiring protection film, and (f) shows the patterning of the interlayer insulating film and the wiring protection film. It is a figure which shows the manufacturing process of the head unit of a modification form, (a) shows adhesion | attachment of a reservoir formation member, (b) shows a pressure chamber formation, (c) shows a sealing film removal, (d) shows a thick film removal. .

  Next, an embodiment of the present invention will be described. FIG. 1 is a schematic plan view of the printer according to the present embodiment. First, a schematic configuration of the inkjet printer 1 will be described with reference to FIG. Note that the front, rear, left, and right directions shown in FIG. 1 are defined as “front”, “rear”, “left”, and “right” of the printer. The front side of the paper is defined as “upper”, and the other side of the paper is defined as “lower”. In the following, description will be made by using the front, rear, left, right, upper, and lower direction words as appropriate.

(Schematic configuration of printer)
As shown in FIG. 1, the inkjet printer 1 includes a platen 2, a carriage 3, an inkjet head 4, a transport mechanism 5, a control device 6, and the like.

  On the upper surface of the platen 2, a recording paper 100 as a recording medium is placed. The carriage 3 is configured to be able to reciprocate in the left-right direction (hereinafter, also referred to as a scanning direction) along two guide rails 10 and 11 in a region facing the platen 2. An endless belt 14 is connected to the carriage 3, and the carriage 3 moves in the scanning direction by driving the endless belt 14 by a carriage drive motor 15.

  The inkjet head 4 is attached to the carriage 3 and moves in the scanning direction together with the carriage 3. The inkjet head 4 includes four head units 16 arranged in the scanning direction. The four head units 16 are connected to the cartridge holders 7 on which the ink cartridges 17 of four colors (black, yellow, cyan, and magenta) are mounted by tubes (not shown). Each head unit 16 has a plurality of nozzles 24 (see FIGS. 2 and 3) formed on its lower surface (the surface on the other side of the paper surface of FIG. 1). The nozzles 24 of each head unit 16 discharge the ink supplied from the ink cartridge 17 toward the recording paper 100 placed on the platen 2.

  The transport mechanism 5 has two transport rollers 18 and 19 arranged so as to sandwich the platen 2 in the front-rear direction. The transport mechanism 5 transports the recording paper 100 placed on the platen 2 forward (hereinafter also referred to as a transport direction) by two transport rollers 18 and 19.

  The control device 6 includes a read only memory (ROM), a random access memory (RAM), an application specific integrated circuit (ASIC) including various control circuits, and the like. The control device 6 executes various processes such as printing on the recording paper 100 by the ASIC according to the program stored in the ROM. For example, in the printing process, the control device 6 controls the inkjet head 4 and the carriage drive motor 15 and the like based on a print command input from an external device such as a PC to print an image or the like on the recording paper 100. . Specifically, an ink ejection operation for ejecting ink while moving the inkjet head 4 in the scanning direction together with the carriage 3 and a transport operation for transporting the recording paper 100 by a predetermined amount in the transport direction by the transport rollers 18 and 19 are alternately performed. To be performed.

(Details of inkjet head)
Next, the configuration of the head unit 16 of the inkjet head 4 will be described in detail. Since the four head units 16 have the same configuration, one of the four head units 16 will be described below.

  FIG. 2 is a plan view of the head unit 16. FIG. 3 is a sectional view taken along line III-III of FIG. As shown in FIGS. 2 and 3, the head unit 16 includes a nozzle plate 20, a flow path substrate 21, a piezoelectric actuator 22 including a plurality of piezoelectric elements 31, a reservoir forming member 23, and the like. In FIG. 2, for simplification of the drawing, the COF 50 and the reservoir forming member 23 joined to the upper surface of the flow path substrate 21 are schematically indicated by a two-dot chain line.

(Nozzle plate)
The nozzle plate 20 is a plate formed of, for example, silicon or the like. The nozzle plate 20 has a plurality of nozzles 24 formed therein. As shown in FIG. 2, the plurality of nozzles 24 are arranged in a staggered manner along the transport direction, and form two nozzle rows arranged in the scanning direction. That is, when the arrangement pitch of the nozzles 24 in one nozzle row is P, the position of the nozzle 24 is shifted by P / 2 in the transport direction between the two left and right nozzle rows.

(Channel substrate)
The channel substrate 21 is a silicon single crystal substrate. A plurality of pressure chambers 26 respectively communicating with the plurality of nozzles 24 are formed in the flow path substrate 21. Each pressure chamber 26 has a rectangular planar shape that is long in the scanning direction. The plurality of pressure chambers 26 are arranged in accordance with the arrangement of the plurality of nozzles 24 described above, and constitute two pressure chamber rows arranged in the scanning direction. The lower surface of the flow path substrate 21 is covered with the nozzle plate 20, and the outer end of each pressure chamber 26 in the scanning direction overlaps the nozzle 24 when viewed from above and below. That is, as shown in FIG. 2, the right end of each pressure chamber 26 and the nozzle 24 overlap in the right pressure chamber row, and the left end of each pressure chamber 26 and the nozzle 24 in the left pressure chamber row. Are overlapping.

  An insulating film 30 is provided on the upper surface of the flow path substrate 21 so as to cover the plurality of pressure chambers 26. The insulating film 30 is, for example, a silicon dioxide film formed by oxidizing the surface of a silicon substrate. The thickness of the insulating film 30 is, for example, 1.0 to 1.5 μm. A through hole 30a is formed in a portion of the insulating film 30 that covers an inner end (an end opposite to the nozzle 24) of each pressure chamber 26. The through-hole 30a forms a part of a flow path for individually supplying ink from the reservoir forming member 23 described later to each of the pressure chambers 26, and has a considerably small diameter, for example, 50 μm or less. . In this embodiment, the insulating film 30 will be described as a film formed of silicon dioxide, but the insulating film 30 may be a film formed of a plurality of layers made of different materials.

  Ink is supplied to each of the pressure chambers 26 from the reservoir 60 in the reservoir forming member 23 described later through the through hole 30a. Then, when ejection energy is applied to the ink in the pressure chamber 26 by the piezoelectric element 31 described below, a droplet of the ink is ejected from the nozzle 24 communicating with the pressure chamber 26.

(Piezoelectric actuator)
The piezoelectric actuator 22 has the above-described insulating film 30 and a plurality of piezoelectric elements 31. The plurality of piezoelectric elements 31 apply discharge energy for discharging from the nozzles 24 to the ink in the plurality of pressure chambers 26, respectively. As shown in FIGS. 2 and 3, the plurality of piezoelectric elements 31 are arranged on the upper surface of the insulating film 30 corresponding to the pressure chambers 26, respectively.

  The configuration of the piezoelectric element 31 will be described. The piezoelectric element 31 includes a common electrode 32, a piezoelectric body 33, and an individual electrode 34 stacked in this order from the lower side.

  The common electrode 32 is formed on the upper surface of the insulating film 30. In FIG. 2, the common electrode 32 is not shown for simplification of the drawing. However, as shown in FIG. 3, the common electrode 32 is formed over almost the entire upper surface of the insulating film 30. I have. The common electrode 32 is formed of, for example, platinum (Pt). The thickness of the common electrode 32 is, for example, 0.1 μm.

  On the common electrode 32, two piezoelectric bodies 33 are arranged corresponding to the two pressure chamber rows, respectively. Each piezoelectric body 33 is formed by patterning a piezoelectric film 37 formed of a piezoelectric material such as lead zirconate titanate (PZT). The piezoelectric film 37 may be made of a lead-free piezoelectric material containing no lead, in addition to PZT. The thickness of the piezoelectric body 33 is, for example, 1.0 to 2.0 μm. In addition, the piezoelectric body 33 has a planar shape that is long in the transport direction, and is disposed so as to straddle the plurality of pressure chambers 26 forming the corresponding pressure chamber row in the transport direction.

  A plurality of individual electrodes 34 are formed on the upper surface of the piezoelectric body 33 at positions facing the plurality of pressure chambers 26, respectively. Each individual electrode 34 has a rectangular planar shape slightly smaller than the pressure chamber 26, and is disposed so as to overlap the center of the corresponding pressure chamber 26. The individual electrode 34 is formed of, for example, iridium (Ir) or platinum (Pt). The thickness of the individual electrode 34 is, for example, 0.1 μm.

  In the above configuration, one pressure chamber 26 is sandwiched between the individual electrode 34 and the portion of the common electrode 32 facing the pressure chamber 26 and between the individual electrode 34 of the piezoelectric body 33 and the common electrode 32. One part of the piezoelectric element 31 is constituted by the part thus removed. The portion of the piezoelectric body 33 sandwiched between the common electrode 32 and one individual electrode 34 is hereinafter referred to as an active portion 36. In each piezoelectric element 31, when an electric field acts between the individual electrode 34 and the common electrode 34, the active portion 36 is deformed in the plane direction. With the deformation of the active portion 36, the piezoelectric element 31 is deformed so as to be entirely bent, and the portion facing the pressure chamber 26 is displaced in the vertical direction orthogonal to the surface direction of the insulating film 30.

  As shown in FIG. 3, the piezoelectric actuator 22 includes a piezoelectric protective film 40, an interlayer insulating film 41, a wiring 42, and a wiring protective film 43. In FIG. 2, the illustration of the piezoelectric protective film 40, the interlayer insulating film 41, and the wiring protective film 43 is omitted for simplification of the drawing.

As shown in FIG. 3, the piezoelectric body protection film 40 is disposed so as to cover the two piezoelectric bodies 33. The piezoelectric body protection film 40 is a film for protecting the piezoelectric body 33 (piezoelectric film 37), for example, by preventing moisture in the air from entering the piezoelectric body 33. The individual electrodes 34 on the upper surface of the piezoelectric body 33 are covered only with the piezoelectric protective film 40 at the peripheral edge, and the central part of the individual electrode 34 is exposed from the piezoelectric protective film 40. Thereby, deformation inhibition of the piezoelectric body 33 due to the provision of the piezoelectric body protective film 40 on the piezoelectric body 33 is suppressed. The piezoelectric protective film 40 is made of, for example, an oxide such as aluminum oxide (alumina: Al ₂ O ₃ ), silicon oxide (SiOx), or tantalum oxide (TaOx), or a nitride such as silicon nitride (SiN). It is formed of a material having low properties. The piezoelectric protective film 40 is thinner than an interlayer insulating film 41 and a wiring protective film 43, which will be described later, and has a thickness of, for example, 30 to 100 nm in order to suppress deformation inhibition of the piezoelectric body 33.

On the piezoelectric protective film 40, an interlayer insulating film 41 is formed. The material of the interlayer insulating film 41 is not particularly limited, but is formed of, for example, silicon dioxide (SiO ₂ ). The thickness of the interlayer insulating film 41 is, for example, 0.3 to 0.5 μm. The interlayer insulating film 41 is provided to enhance insulation between the common electrode 32 and the wiring 42 described below connected to the individual electrode 34.

  A plurality of wirings 42 connected to the individual electrodes 34 of the plurality of piezoelectric elements 31 are formed on the interlayer insulating film 41. The thickness of the wiring 42 is, for example, 1.0 μm. The individual electrode 34 and the wiring 42 are electrically connected by a conductive portion 48 penetrating the piezoelectric protective film 40 and the interlayer insulating film 41. The wiring 42 is formed of a material having a low electrical resistivity, such as aluminum (Al) or gold (Au). Each wiring 42 is drawn rightward from the corresponding individual electrode 34 and extends to the right end of the flow path substrate 21 exposed from the reservoir forming member 23.

  Each wiring 42 extends to the right end of the flow path substrate 21 along the surface of the interlayer insulating film 41. A plurality of drive contacts 46 having a width larger than the wiring 42 are arranged on the upper surface of the right end of the flow path substrate 21 in the transport direction. The plurality of wirings 42 are connected to the plurality of drive contacts 46, respectively. At the right end of the flow path substrate 21, a ground contact 47 is also arranged on the surface of the interlayer insulating film 41. The ground contact 47 is provided via the common electrode 32 located below the interlayer insulating film 41 and the piezoelectric protective film 40, and via a contact hole (not shown) formed in the interlayer insulating film 41 and the piezoelectric protective film 40. Conducted. Note that the wiring 42, the drive contact 46, and the ground contact 47 can be formed in the same film forming process.

  As shown in FIGS. 2 and 3, the through-hole 30a of the insulating film 30 is surrounded by annular conductive portions 44 and 45 formed of the same material as the wiring 42. In the through hole 30a corresponding to the left pressure chamber row, the annular conductive portion 44 is electrically connected to the wiring 42 drawn from the left individual electrode 34. That is, the annular conductive part 44 forms a part of the wiring 42. On the other hand, in the through hole 30a corresponding to the right pressure chamber row, the annular conductive portion 45 is independent from the wiring 42 without conduction. Since the through holes 30a are surrounded by the annular conductive portions 44 and 45, the sealing performance with respect to the through holes 30a when the reservoir forming member 23 described later is joined to the flow path substrate 21 is enhanced. The width of the annular conductive portions 44 and 45 extending in the annular shape is, for example, 2.5 to 10 μm.

  As shown in FIG. 3, the wiring protection film 43 is disposed so as to cover the plurality of wirings 42. By covering the plurality of wirings 42 with the wiring protection film 43, insulation between the plurality of wirings 42 is enhanced. The wiring protection film 43 is formed of, for example, silicon nitride (SiNx). The thickness of the wiring protection film 43 is, for example, 0.1 to 1 μm. Note that the wiring protection film 43 is not provided at the right end of the flow path substrate 21, and the drive contact 46 and the ground contact 47 are not covered by the wiring protection film 43.

  As shown in FIGS. 2 and 3, one end of the COF 50 is joined to the upper surface of the right end of the flow path substrate 21 where the drive contact 46 and the ground contact 47 are exposed. A driver IC 51 is mounted in the middle of the COF 50. The other end of each COF 50 is connected to the control device 6 of the printer 1 (see FIG. 1). In the COF 50, a plurality of drive wirings 52 and a ground wiring (not shown) are formed. Each drive wiring 52 is connected to an output terminal of the driver IC 51. When the COF 50 is joined to the right end of the flow path substrate 21, the drive wiring 52 is electrically connected to the corresponding drive contact 46, and the ground wiring is electrically connected to the ground contact 47.

  The driver IC 51 generates a drive signal based on a control signal from the control device 6 and outputs the drive signal to each piezoelectric element 31. The drive signal is input to the drive contact 46 via the drive wiring 52, and further supplied to the corresponding individual electrode 34 via the wiring 42. At this time, the potential of the individual electrode 34 changes between a predetermined drive potential and a ground potential. The potential of the common electrode 32 is maintained at the ground potential.

  The operation of each piezoelectric element 31 when a drive signal is supplied from the driver IC 51 will be described. When no drive signal is input, the potential of the individual electrode 34 is the ground potential, which is the same potential as the common electrode 32. When a drive signal is input to the individual electrode 34 from this state, an electric field in the thickness direction acts on the active portion 36 of the piezoelectric body 33 due to a potential difference from the common electrode 32. At this time, the active portion 36 on the insulating film 30 is deformed, and the entire piezoelectric element 31 is bent so as to protrude toward the pressure chamber 26. As a result, the volume of the pressure chamber 26 is reduced and a pressure wave is generated in the pressure chamber 26, and ink droplets of ink are ejected from the nozzle 24 communicating with the pressure chamber 26.

(Reservoir forming member)
As shown in FIG. 2, the reservoir forming member 23 is disposed on the upper surface of the flow path substrate 21 (insulating film 30) so as to cover the plurality of piezoelectric elements 31, and is bonded to the flow path substrate 21 with a thermosetting adhesive. Is done. The material of the reservoir forming member 23 is not particularly limited, but may be a silicon substrate like the channel substrate 21 or may be formed of another material such as a resin. Further, the reservoir forming member 23 may be formed by stacking a plurality of plates made of different materials.

  Above the reservoir forming member 23, a reservoir 60 for storing ink is formed. The reservoir 60 is supplied with ink from the ink cartridge 17 of the holder 5 (see FIG. 1).

  In the lower part of the reservoir forming member 23, two concave portions 63 respectively corresponding to the two piezoelectric bodies 33 are formed. When the reservoir forming member 23 is joined to the upper surface of the flow path substrate 21, the two piezoelectric bodies 33 are accommodated in the two concave portions 63, respectively.

  As shown in FIGS. 2 and 3, a plurality of through holes 30 a described above are opened in a region between the two piezoelectric bodies 33 on the upper surface of the flow path substrate 21. On the other hand, a plurality of flow passage holes 64 are formed in a wall portion 65 of the reservoir forming member 23 that divides the concave portion 63. When the wall portion 65 of the reservoir forming member 23 is bonded to a region between the two piezoelectric bodies 33 of the flow path substrate 21, the plurality of flow paths 64 communicate with the plurality of through-holes 30a, respectively. The diameter of the passage hole 64 of the reservoir forming member 23 is smaller than that of the through hole 30 a of the insulating film 30. The ink stored in the reservoir 60 is supplied to the plurality of pressure chambers 26 via the plurality of passage holes 64 and the plurality of through holes 30a.

(Manufacturing process of head unit)
Next, a manufacturing process of one head unit 16 of the above-described inkjet head 4 will be described with reference to FIGS.

  First, the piezoelectric element 31 is formed on the flow path substrate 21. (A) is a vibration film formation, (b) is a common electrode film formation, (c) is a piezoelectric film formation, (d) is an individual electrode film formation, (e) is an individual electrode patterning, and (f) is a piezoelectric body patterning. , (G) show common electrode patterning.

  First, as shown in FIG. 4A, an insulating film 30 of silicon dioxide is formed on the surface of a flow path substrate 21 of silicon by thermal oxidation or the like. Next, as shown in FIG. 4B, a conductive film 70 to be the common electrode 32 such as platinum (Pt) is formed on the insulating film 30 by sputtering or the like.

  Next, as shown in FIG. 4C, a piezoelectric film 37 made of a piezoelectric material such as PZT is formed on the conductive film 70 (common electrode 32) by a sol-gel method, sputtering, or the like. Further, as shown in FIG. 4D, a conductive film 71 to be a plurality of individual electrodes 34 such as iridium (Ir) or platinum (Pt) is formed on the upper surface of the piezoelectric film 37 by sputtering or the like.

  Next, as shown in FIG. 4E, the conductive film 71 is patterned by, for example, dry etching to form the individual electrodes 34. Further, as shown in FIG. 4F, the piezoelectric film 33 is formed by patterning the piezoelectric film 37 by, for example, dry etching. Further, as shown in FIG. 4G, the conductive film 70 below the piezoelectric body 33 is also patterned to form the common electrode 32. Through the above steps, the piezoelectric element 31 is formed on the insulating film 30.

  5A shows the formation of a piezoelectric protective film, FIG. 5B shows the patterning of the piezoelectric protective film, FIG. 5C shows the formation of an interlayer insulating film, FIG. 5D shows the formation of wiring, and FIG. (F) shows the formation of a wiring protection film (sealing film), and (g) shows the patterning of the interlayer insulating film and the wiring protection film.

  After the piezoelectric element 31 is formed on the flow path substrate 21, as shown in FIG. 5A, alumina or the like is formed on the entire upper surface of the insulating film 30 by a film forming method such as sputtering so as to cover the entire piezoelectric body 33. Is formed. Further, as shown in FIG. 5B, the piezoelectric protective film 40 is patterned by etching. By this patterning, a portion of the piezoelectric protective film 40 overlapping the individual electrode 34 is removed to form a hole 40c. Also, in a region where the through hole 30a is formed in the insulating film 30 later, the piezoelectric protective film 40 is removed to form a hole 40b. The hole 40b and the hole 40c may be formed in the same etching step, or may be formed in different etching steps.

  As shown in FIG. 5C, an interlayer insulating film 41 of silicon dioxide is formed on the piezoelectric protective film 40 by a film forming method such as plasma CVD or sputtering. After the film formation, a hole 41a is formed in a portion covering the piezoelectric protective film 40 by etching. At this time, a hole 40a connected to the hole 41a of the interlayer insulating film 41a is formed in the piezoelectric film protective film 40 at the same time.

  As shown in FIG. 5D, a plurality of wirings 42 are formed on the interlayer insulating film 41. First, an aluminum conductive film is formed on almost the entire upper surface of the interlayer insulating film 41 by sputtering or the like. At this time, the conductive material is also filled in the holes 40a and 41a to form the conductive portion 48. Next, unnecessary portions are removed by patterning the conductive film by etching, and a plurality of wirings 42 are formed. In the above-mentioned patterning, the annular conductive portion 44 (45) is formed in a region of the insulating film 30 where the through hole 30a is formed (a region where the common electrode 32 and the piezoelectric protective film 40 are partially removed). To form After the formation of the wiring 42, as shown in FIG. 5E, the regions inside the annular conductive portion 44 (45) of the insulating film 30 and the interlayer insulating film 41 formed of silicon dioxide are removed at one time by etching. Through holes 30a and 41b are formed in each film.

  Next, as shown in FIG. 5F, a wiring protection film 43 of silicon nitride (SiNx) is formed over substantially the entire surface of the insulating film 30 by a film forming method such as sputtering in addition to plasma CVD. The wirings 42 are covered with the wiring protection film 43. In addition, the wiring protection film 43 is formed so as to continuously cover from the through hole 30a to the insulating film 30 around the through hole 30a, and has a sufficient area outside the through hole 30a with a film such as the insulating film 30 or the like. Overlap.

  First, the through hole 30a is formed in the insulating film 30, and then the wiring protection film 43 is formed, whereby the wiring protection film 43 covers the through hole 30a of the insulating film 30 from above and covers the through hole 30a. It is arranged to seal. The portion of the wiring protection film 43 that covers the through hole 30 a is in direct contact with the surface of the flow path substrate 21. That is, the wiring protection film 43 also serves as the sealing film 72 for sealing the through hole 30a, and prevents leakage of the etching solution when the pressure chamber 26 is formed in the flow path substrate 21 by wet etching in a later process. It has the role of an etching stop to prevent. Conversely, by forming the sealing film 72 covering the through hole 30a so as to cover the plurality of wirings 42, it can be said that the sealing film 72 and the wiring protection film 43 are formed by the same process. The number can be reduced.

  In this embodiment, after the piezoelectric element 31 is formed on the insulating film 30, the sealing film 72 is formed by film formation. When forming the piezoelectric element 31, high-temperature heat of 600 to 800 ° C. acts on the flow path substrate 21. However, by forming the sealing film 72 after forming the piezoelectric element 31, the heat applied to the sealing film 72 is reduced. The effects of stress and the like can be suppressed.

  After the formation of the wiring protection film 43, as shown in FIG. 5G, the regions of the interlayer insulating film 41 and the wiring protection film 43 which cover the individual electrodes 34 are removed by etching. Through the above steps, the formation of the piezoelectric actuator 22 on the flow path substrate 21 is completed.

  FIG. 6A shows the adhesion of the reservoir forming member, FIG. 6B shows the formation of the pressure chamber, and FIG. 6C shows the removal of the sealing film.

  Next, as shown in FIG. 6A, the reservoir forming member 23 is attached to the flow path substrate 21 using the thermosetting adhesive 73 in a state where the piezoelectric actuator 22 is interposed between the reservoir formation member 23 and the flow path substrate 21. Glue. At this time, the reservoir forming member 23 is also arranged via the adhesive 73 on the sealing film 72 for sealing the through hole 30a of the insulating film 30.

  After the adhesion of the reservoir forming member 23, the thickness of the flow path substrate 21 is reduced (for example, 100 μm) by polishing the lower surface of the flow path substrate 21 on the side opposite to the insulating film 30. Although the rigidity of the flow path substrate 21 itself decreases as the thickness decreases, the above-mentioned decrease in rigidity is compensated for by the fact that the reservoir forming member 23 is bonded to the flow path substrate 21 before polishing.

  After the polishing of the flow path substrate 21, as shown in FIG. 6B, anisotropic wet etching is performed from the lower surface of the flow path substrate 21 (the surface opposite to the insulating film 30), A plurality of pressure chambers 26 are formed at positions respectively overlapping the plurality of through holes 30a. As an etchant for anisotropic wet etching of a silicon single crystal substrate, for example, a TMAH (tetramethylammonium hydroxide) aqueous solution or a KOH aqueous solution is generally used. Here, the through hole 30 a of the insulating film 30 is sealed by the sealing film 72. Further, silicon nitride (SiNx) constituting the sealing film 72 (wiring protection film 43) has higher resistance to the above-described etching solution than the silicon single crystal flow path substrate 21. That is, the sealing film 72 is less likely to be removed by wet etching than the flow path substrate 21. Therefore, the sealing film 72 functions as an etching stop film, and prevents the etchant from leaking from the through hole 30a to the reservoir forming member 23 side.

  Here, when the sealing film 72 (wiring protection film 43) is formed so as to cover the insulating film 30 and the through hole 30a, the sealing film 72 covers not only the entire through hole 30a, but also It is formed so as to continuously extend from the through hole 30a to a region outside the through hole 30a. In the present embodiment, the sealing film 72 has a portion 72a covering the through hole 30a, an annular portion 72b surrounding the through hole 30a, and another portion 72c. The annular portion 72b of the sealing film 72 overlaps the common electrode 32, the piezoelectric protective film 40, the interlayer insulating film 41, and the annular conductive portion 44 (45) of the wiring 42. That is, the sealing film 72 has a sufficient area overlapping the region of the insulating film 30 outside the through hole 30a. Accordingly, when the pressure chamber 26 is formed by wet etching, even when an external force acts on the sealing film 72, for example, when a liquid pressure of an etching solution is applied from below, the sealing film 72 is not easily damaged. Note that the width of the annular portion 72b around the through hole 30a of the sealing film 72 is preferably 1.0 μm or more.

After the formation of the pressure chamber 26, a portion of the sealing film 72 covering the through hole 30a is removed. In the present embodiment, as shown in FIG. 6C, the sealing film 72 is removed by dry etching from below the flow path substrate 21. As an etching gas for the dry etching, for example, carbon tetrafluoride (CF ₄ ) or a mixed gas of such gas and oxygen gas is used.

  In dry etching, pattern control can be performed with higher precision than in wet etching, and precise shape processing is possible. Therefore, by removing the sealing film 72 covering the through hole 30a by dry etching, the sealing film 72 can be removed with high accuracy. Further, when the diameter of the through hole 30a is small, problems such as flow path resistance variation caused by low etching accuracy cannot be ignored. In particular, when the through hole 30a is as small as 50 μm or less, it is particularly effective to remove the sealing film 72 by dry etching which enables high-definition processing.

Further, silicon nitride forming the sealing film 72 (wiring protection film 43) has lower etching resistance to dry etching using an etching gas such as CF ₄ than the silicon dioxide insulating film 30. That is, the sealing film 72 is formed of a material that is more easily removed by dry etching than the insulating film 30. Therefore, the sealing film 72 is promptly removed by dry etching, while the insulating film 30 is not easily removed.

  After removing the sealing film 72 by dry etching, the nozzle plate 20 is adhered to the lower surface of the flow path substrate 21 on the side opposite to the insulating film 30, although not shown. Thus, the manufacture of the head unit 16 is completed.

  In the embodiment described above, the head unit 16 of the inkjet head 4 corresponds to the “liquid ejection device” of the present invention. The flow path substrate 21 corresponds to the “substrate” of the present invention. The reservoir forming member 23 corresponds to the “flow path member” of the present invention.

  Next, modified embodiments in which various changes are made to the above-described embodiment will be described. However, the components having the same configuration as the above embodiment are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

  In the embodiment, the sealing film 72 that covers the through hole 30a of the insulating film 30 is formed so as to cover the plurality of wirings 42, so that the sealing film 72 and the wiring protection film 43 are formed in the same process. However, the present invention is not limited to the above embodiment.

1) The sealing film and the piezoelectric protection film 40 covering the piezoelectric body 33 may be formed by the same process. Hereinafter, a description will be given with reference to FIGS. 7 and 8, but the steps up to forming the piezoelectric element 31 are the same as those in FIG. 7A shows the formation of a through hole in a vibration film, FIG. 7B shows the formation of a piezoelectric protective film, FIG. 7C shows the formation of an interlayer insulating film, FIG. 7D shows the formation of wiring, and FIG. And (f) shows patterning of the insulating film and the wiring protection film.

After the piezoelectric element 31 is formed on the insulating film 30 provided on the flow path substrate 21, a through hole 30a is formed in a part of the silicon dioxide insulating film 30 by etching, as shown in FIG. Next, as shown in FIG. 7B, a piezoelectric protective film 40 such as alumina (Al ₂ O ₃ ) is formed so as to cover the insulating film 30, the through hole 30a, and the piezoelectric body 33. As described in the above embodiment, the piezoelectric protective film 40 is formed to be considerably thinner than the insulating film 30 in order to suppress deformation inhibition of the piezoelectric body 33. For example, the thickness of the insulating film 30 is 1.0 to 1.5 μm, and the thickness of the piezoelectric protection film 40 is 30 to 100 nm.

  The piezoelectric protective film 40 also functions as a sealing film 82 for sealing the through hole 30a of the insulating film 30. In other words, by forming the sealing film 82 so as to cover the piezoelectric film constituting the piezoelectric body 33, the sealing film 82 and the piezoelectric protection film 40 are formed in the same process. This means that the number of steps can be reduced. After the formation of the piezoelectric protective film 40, an interlayer insulating film 41 of silicon dioxide is formed as shown in FIG.

  Next, as shown in FIG. 7D, a wiring 42 connected to the individual electrode 34 is formed on the interlayer insulating film 41. After the formation of the wiring 42, as shown in FIG. 7E, a wiring protection film 43 of silicon nitride is formed so as to cover the wiring 42. Further, as shown in FIG. 7F, the interlayer insulating film 41 and the wiring protection film 43 are patterned by etching. Thus, portions of the interlayer insulating film 41 and the wiring protection film 43 that cover the individual electrodes 34 are removed. At this time, the interlayer insulating film 41 and the wiring protection film 43 on the sealing film 82 are also removed, and the through-hole 30a is sealed with the sealing film 82 only.

  8A shows the adhesion of the reservoir forming member, FIG. 8B shows the formation of the pressure chamber, FIG. 8C shows the removal of the sealing film 82, and FIG. 8D shows the removal of the thick film.

  Next, as shown in FIG. 8A, the reservoir forming member 23 is adhered to the flow path substrate 21 using a thermosetting adhesive 73. Here, the sealing film 82 that covers the through-hole 30a of the insulating film 30 is a thin film and has low strength. Therefore, it is preferable that the sealing film 82 be provided with a thick reinforcing film 83. In this embodiment, a thick film 83 thicker than the sealing film 82 is formed on the entire surface of the portion of the sealing film 82 covering the through-hole 30a with an adhesive 73 for bonding the reservoir forming member 23. The thickness of the thick film 83 of the adhesive 73 is, for example, 0.5 to 2 μm. Further, since the thick film 83 for reinforcing the sealing film 82 is formed with the adhesive 73 for bonding the reservoir forming member 23, the thick film 83 can be formed together with the bonding step, and the number of steps is reduced. be able to.

  Note that the thick film 83 does not necessarily need to be formed with the adhesive 73, and may be a resin material such as a resist. Alternatively, in patterning at the time of forming the wiring 42, the aluminum conductive film present on the sealing film 82 is intentionally left without being removed, and the conductive film is thickened to reinforce the sealing film 82. It may be used as the film 83.

  Further, the thick film 83 does not need to be formed over the entire region of the sealing film 82 that covers the through-hole 30a, and may be formed only over a part of the above-described region. For example, the thick film 83 may be formed only in a region overlapping with the peripheral portion of the through hole 30a. As the formation region of the thick film 83 on the sealing film 82 becomes smaller, the reinforcing effect of the sealing film 82 decreases, but the thick film 83 is easily removed in a later step.

  Next, as shown in FIG. 8B, a plurality of pressure chambers 26 are formed in the flow path substrate 21 by anisotropic wet etching from below the flow path substrate 21 (the side opposite to the insulating film 30). . Here, the through holes 30 a of the insulating film 30 are sealed by the sealing film 82. The oxide such as alumina that forms the sealing film 82 is a material that is not easily removed by the etchant for the silicon single crystal flow path substrate 21. Therefore, the sealing film 82 prevents the etchant from leaking to the reservoir forming member side.

  Further, if the sealing film 82 is thin, it is likely to be damaged when liquid pressure acts on a portion of the sealing film 82 that covers the through hole 30a during wet etching of the pressure chamber 26. In this regard, since the thick film 83 is formed on the portion of the sealing film 82 that covers the through hole 30a to reinforce the sealing film 82, breakage caused when hydraulic pressure acts on the sealing film 82 is suppressed. .

  After forming the pressure chamber 26, as shown in FIG. 8C, the sealing film 82 formed of alumina or the like is removed by dry etching from the surface of the flow path substrate 21 opposite to the insulating film 30. . Here, since the sealing film 82 is a film thinner than the insulating film 30, the sealing film 82 can be promptly removed by dry etching, and the insulating film 30 can be prevented from being scraped.

  It should be noted that a situation in which the sealing film 82 is more easily etched than the insulating film 30 can be created by selecting the type of dry etching gas. For example, when a chlorine-based gas is used, alumina is etched at a much higher rate than silicon dioxide (see, for example, JP-A-2009-81271). Therefore, when the sealing film 82 is formed of alumina and the insulating film 30 is formed of silicon dioxide, the chlorine-based gas can be used to quickly remove the sealing film 82 of alumina.

  After removing the sealing film 82, the thick film 83 is removed as shown in FIG. For example, when the thick film 83 is formed of a resin material such as an adhesive or a resist, the thick film 83 is removed by oxygen plasma. If the thick film 83 is a conductive film such as aluminum, it is removed by dry etching using a chlorine-based gas or the like.

2) It is not always necessary to form the sealing film by the same process as a film having another function. That is, there may be a step of forming only the sealing film alone. In this case, the sealing film may be formed at any timing after forming the through-hole 30a in the insulating film 30. For example, a sealing film may be formed after forming the through-holes 30 a in the insulating film 30 and before forming the piezoelectric elements 31 in the insulating film 30.

3] In FIG. 3 of the embodiment, a plurality of films constituting the piezoelectric actuator 22, such as the insulating film 30, the lower electrode 31, and the piezoelectric protective film 40, are formed on the flow path substrate 21 by film formation. The reservoir forming member 23 is adhered thereon. That is, the reservoir forming member 23 is bonded to the flow path substrate 21 via the plurality of films. On the other hand, while the plurality of films are formed only in a part of the upper surface of the flow path substrate 21, the reservoir forming member 23 is adhered to an area of the flow path substrate 21 where the plurality of films are not formed. You may.

  The embodiments described above and the modifications thereof apply the present invention to an ink jet head that prints an image or the like by discharging ink onto recording paper, but may be used in various applications other than printing of an image or the like. The present invention can be applied to a liquid ejecting apparatus that uses the present invention. For example, the present invention can be applied to an industrial liquid discharge device that discharges a conductive liquid to a substrate to form a conductive pattern on the substrate surface.

REFERENCE SIGNS LIST 1 inkjet printer 4 inkjet head 16 head unit 21 flow path substrate 23 reservoir forming member 24 nozzle 26 pressure chamber 30 vibration film 30a through hole 31 piezoelectric element 33 piezoelectric body 37 piezoelectric film 40 piezoelectric body protection film 41 interlayer insulation film 42 wiring 43 wiring Protective film 64 Channel hole 72 Sealing film 73 Adhesive 82 Sealing film 83 Thick film

Claims (15)

An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching to form a through hole in the insulating film;
A sealing film forming step of forming a sealing film covering the insulating film and the through hole;
A bonding step of bonding a flow path member formed with a flow path communicating with the through hole to the substrate,
A pressure chamber forming step of forming a pressure chamber in the substrate at a position overlapping with the through hole of the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed;
Removing the portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to the surface on which the insulating film is formed, a sealing film removing step;
A piezoelectric element forming step of forming a piezoelectric element on the insulating film;
A wiring forming step of forming a wiring connected to the piezoelectric element on the insulating film;
With
After the piezoelectric element forming step, the sealing film is formed, and
In the sealing film forming step, the sealing film is formed using a material having an etching resistance to dry etching in the sealing film removing step lower than the etching resistance of the insulating film; A method for manufacturing a liquid ejecting apparatus , comprising forming a film so as to cover the wiring, thereby forming a wiring protection film . An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching to form a through hole in the insulating film;
A sealing film forming step of forming a sealing film covering the insulating film and the through hole;
A bonding step of bonding a flow path member formed with a flow path communicating with the through hole to the substrate,
A pressure chamber forming step of forming a pressure chamber in the substrate at a position overlapping with the through hole of the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed;
Removing the portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to the surface on which the insulating film is formed, a sealing film removing step;
Equipped with a,
In the insulating film forming step, the insulating film is formed of silicon dioxide,
In the sealing film forming step, the sealing film is formed of a material having an etching resistance to dry etching in the sealing film removing step lower than the etching resistance of the insulating film; A method for manufacturing a liquid discharge device, wherein a film is formed of silicon nitride . An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching to form a through hole in the insulating film;
A sealing film forming step of forming a sealing film covering the insulating film and the through hole;
A bonding step of bonding a flow path member formed with a flow path communicating with the through hole to the substrate,
A pressure chamber forming step of forming a pressure chamber in the substrate at a position overlapping with the through hole of the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed;
Removing the portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to the surface on which the insulating film is formed, a sealing film removing step;
Equipped with a,
The method of manufacturing a liquid ejection device , wherein in the sealing film forming step, the sealing film is formed thinner than the insulating film . A piezoelectric element forming step of forming a piezoelectric element on the insulating film,
The method according to claim 3 , wherein the sealing film is formed after the piezoelectric element forming step. The liquid according to claim 4 , wherein, in the sealing film forming step, the sealing film is formed so as to cover a piezoelectric film of the piezoelectric element, thereby forming a piezoelectric film protection portion. Manufacturing method of discharge device. In the insulating film forming step, the insulating film is formed of silicon dioxide,
The method according to claim 3 , wherein the sealing film is formed of aluminum oxide in the sealing film forming step. A thick film forming step of forming a thick film thicker than the sealing film on at least a part of a region covering the through hole on the sealing film,
The method according to any one of claims 3 to 6 , further comprising a thick film removing step of removing the thick film after the pressure chamber forming step. The method according to claim 7 , wherein the thick film is formed of a resin material. 9. The method according to claim 8 , wherein the thick film is formed of an adhesive that bonds the substrate and the flow path member in the bonding step. The method according to claim 1, wherein a diameter of the through hole is 50 μm or less. An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching to form a through hole in the insulating film;
A sealing film forming step of forming a sealing film, which is an insulating film, covering the insulating film and the through hole;
A bonding step of bonding a flow path member formed with a flow path communicating with the through hole to the substrate,
A pressure chamber forming step of forming a pressure chamber in the substrate at a position overlapping with the through hole of the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed;
Removing the portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to the surface on which the insulating film is formed, a sealing film removing step;
A method for manufacturing a liquid ejecting apparatus, comprising: A method for manufacturing a liquid ejection device having a plurality of nozzles arranged along a predetermined direction,
An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching, a through-hole forming step of forming a plurality of through-holes corresponding to the plurality of nozzles, arranged in the insulating film along the predetermined direction ;
A sealing film forming step of forming a sealing film covering the insulating film and the plurality of through holes ,
A bonding step of bonding a flow path member having a flow path communicating with the plurality of through holes to the substrate,
Forming a plurality of pressure chambers in the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed, at a position overlapping with each of the plurality of through holes ; Process and
A portion of the sealing film covering each of the plurality of through holes is removed by dry etching from a surface of the substrate opposite to a surface on which the insulating film is formed, a sealing film removing step,
A method for manufacturing a liquid ejecting apparatus, comprising: An insulating film forming step of forming an insulating film on the surface of the substrate;
Removing a part of the insulating film by etching to form a through hole in the insulating film;
A piezoelectric element forming step of forming a piezoelectric element including a common electrode, a piezoelectric body, and an individual electrode on the insulating film,
A sealing film forming step of forming a sealing film covering the insulating film and the through hole;
A bonding step of bonding a flow path member formed with a flow path communicating with the through hole to the substrate,
A pressure chamber forming step of forming a pressure chamber in the substrate at a position overlapping with the through hole of the substrate by wet etching from a surface of the substrate opposite to a surface on which the insulating film is formed;
Removing the portion of the sealing film covering the through hole by dry etching from a surface of the substrate opposite to the surface on which the insulating film is formed, a sealing film removing step;
Equipped with a,
The method of manufacturing a liquid discharge device , wherein in the sealing film forming step, the sealing film is formed to have a thickness equal to or less than a thickness of the piezoelectric body . Board and
An insulating film formed on the surface of the substrate,
A through hole formed in the insulating film;
A film which is an insulating film, which has an annular portion surrounding the through-hole, which covers the insulating film,
A flow path member adhered to the substrate and formed with a flow path communicating with the through hole;
A liquid ejection device, comprising: a pressure chamber formed at a position overlapping the through hole of the substrate, and communicating with the through hole . Board and
An insulating film formed on the surface of the substrate,
A through hole formed in the insulating film;
A film that covers the insulating film and has an annular portion surrounding the through hole, and a film thinner than the insulating film.
A flow path member adhered to the substrate and formed with a flow path communicating with the through hole;
A liquid ejection device, comprising: a pressure chamber formed at a position overlapping the through hole of the substrate, and communicating with the through hole .

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