JP2008168551A - Method of manufacturing liquid ejection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a liquid ejection head which equalizes ejection characteristics of liquid to achieve cost reduction. <P>SOLUTION: There is provided the method of manufacturing the liquid ejection head which is formed of a channel forming substrate 10 in which pressure generating chambers communicating with respective nozzle openings are formed, and piezoelectric elements each consisting of a lower electrode 60, a piezoelectric layer, and an upper electrode which are arranged on one side of the channel forming substrate 10 via diaphragms 50, 55. The method is composed of a step of forming the diaphragms 50, 55 on the one side of the channel forming substrate 10, and forming the vibration film 55 constituting the diaphragm in a manner varying the thickness of the vibration film, based on the displacement of the piezoelectric element; a step of forming the piezoelectric elements on the diaphragm; and a step of forming the pressure generating chambers in the channel forming substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid ejecting head that ejects liquid, and more particularly, to a method for manufacturing an ink jet recording head that ejects ink as a liquid.

  A part of the pressure generation chamber communicating with the nozzle opening for discharging ink droplets is constituted by a vibration plate, and the vibration plate is deformed by a piezoelectric element to pressurize the ink in the pressure generation chamber to discharge ink droplets from the nozzle opening. Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator. For example, a piezoelectric actuator in a flexural vibration mode is used, for example, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique, and the piezoelectric material layer is formed by a lithography method. The piezoelectric element is formed so as to be separated into shapes corresponding to the above and independently for each pressure generating chamber.

  A plurality of such ink jet recording heads are used simultaneously in order to increase the number of nozzle openings. However, since the piezoelectric elements of each ink jet recording head have variations in displacement, variations in ink characteristics such as ink discharge amount occur, and high-precision and high-quality printing cannot be performed.

  For this reason, as an ink jet recording head using a piezoelectric actuator in a longitudinal vibration mode, an elastic member is attached to each piezoelectric actuator, and the range in which the elastic member is attached is changed based on the displacement of each piezoelectric actuator. The thing which suppressed the dispersion | variation in the displacement is proposed (for example, refer patent document 1).

JP 2003-62992 A (pages 3 to 4, FIGS. 2 and 5)

  However, the ink jet recording head of Patent Document 1 uses a longitudinal vibration mode piezoelectric actuator, and requires an elastic member to be attached to the piezoelectric actuator. There is a problem that increases.

  In addition, the piezoelectric elements formed not only between the ink jet recording heads but also on a single substrate vary in the amount of displacement depending on the region, and it is difficult to make the liquid discharge characteristics uniform. There's a problem.

  Such a problem exists not only in the method of manufacturing an ink jet recording head but also in the method of manufacturing a liquid ejecting head that ejects liquid other than ink.

  In view of such circumstances, it is an object of the present invention to provide a method of manufacturing a liquid ejecting head in which the liquid ejection characteristics are uniformized and the cost is reduced.

  An aspect of the present invention that solves the above problems includes a flow path forming substrate provided with a pressure generating chamber communicating with a nozzle opening, and a lower electrode provided on one surface side of the flow path forming substrate via a diaphragm, A method of manufacturing a liquid jet head comprising a piezoelectric element comprising a piezoelectric layer and an upper electrode, wherein the diaphragm is formed on one side of the flow path forming substrate, and the diaphragm comprises the diaphragm A step of changing the thickness based on the amount of displacement of the piezoelectric element, a step of forming the piezoelectric element on the diaphragm, and a step of forming the pressure generating chamber on the flow path forming substrate And a manufacturing method of a liquid ejecting head.

  In this aspect, by changing the thickness of the vibration film according to the displacement amount of the piezoelectric element, it is possible to make the displacement characteristics uniform within the flow path forming substrate surface of the piezoelectric element. In addition, since it is not necessary to attach another member such as an elastic member to the piezoelectric element to make the displacement amount of the piezoelectric element uniform, the number of parts can be reduced and the manufacturing cost can be reduced.

  Here, the vibration plate includes an elastic film provided on the flow path forming substrate and an insulator film provided on the elastic film, and the vibration film includes the elastic film and the insulator film. It is preferable that it is at least one of these. According to this, the amount of displacement of the piezoelectric element can be made uniform by changing the thickness of at least one of the elastic film and the insulator film.

  Moreover, it is preferable that the vibration film is the insulator film made of zirconium oxide. According to this, the thickness of the insulator film made of zirconium oxide can be easily changed with high accuracy.

  Preferably, after the step of forming the pressure generating chamber, the step of measuring the displacement amount of the piezoelectric element, and feeding back the measured displacement amount of the piezoelectric element to change the thickness of the vibration film. . According to this, the amount of displacement of the piezoelectric element can be made uniform with higher accuracy by feeding back the amount of displacement of the piezoelectric element and changing the thickness of the diaphragm.

  In the step of forming the vibration film, the thickness of the vibration film formed in the region where the displacement amount of the piezoelectric element is large is the thickness of the vibration film formed in the region where the displacement amount of the piezoelectric element is small. It is preferable to form it thicker than that. According to this, by forming the vibration film thick in a region where the displacement amount of the piezoelectric element is large, it is possible to make the displacement characteristics uniform within the flow path forming substrate surface of the piezoelectric element.

  In addition, after the diaphragm, the piezoelectric element, and the pressure generating chamber are formed on a flow path forming substrate wafer in which a plurality of the flow path forming substrates are integrally formed, a plurality of the flow path forming substrate wafers are It is preferable to divide the flow path forming substrate. According to this, since the displacement amount of the piezoelectric element can be made uniform by changing the thickness of the vibration film based on the displacement amount of the piezoelectric element, the same displacement can be obtained from one flow path forming substrate wafer. A plurality of liquid jet heads having an amount of piezoelectric elements can be manufactured simultaneously. Accordingly, when a plurality of liquid ejecting heads are combined, the liquid ejecting characteristics of the liquid ejecting heads can be made uniform, and high-precision and high-quality printing can be performed. In addition, since a plurality of liquid ejecting heads formed from one flow path forming substrate wafer can be combined, the liquid ejecting heads for each rank can be prevented from being excessive or insufficient without ranking the liquid ejecting heads. Yield can be improved.

  Further, in the step of forming the vibration film, it is preferable that the vibration film is formed so that the thickness of the vibration film is gradually thicker on the center side than on the peripheral edge side in the plane of the flow path forming substrate wafer. . According to this, the thickness of the vibration film is decreased on the peripheral edge side where the displacement amount of the piezoelectric element is likely to be lowered to increase the displacement amount of the piezoelectric element, and is increased on the center side where the displacement amount of the piezoelectric element is likely to be increased. Thus, the amount of displacement of the piezoelectric element can be made uniform by reducing the amount of displacement of the piezoelectric element.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view showing a schematic configuration of an ink jet recording head which is an example of a liquid jet head according to Embodiment 1 of the present invention. FIG. 2 is a plan view of FIG. 1 and pressure of the ink jet recording head. It is sectional drawing of the longitudinal direction of a generation chamber.

  As shown in the figure, the flow path forming substrate 10 is composed of a silicon single crystal substrate whose crystal plane orientation in the thickness direction is a (110) plane in this embodiment, and one surface thereof is previously composed of silicon dioxide by thermal oxidation. An elastic film 50 having a thickness of 0.5 to 2 μm is formed.

  In the flow path forming substrate 10, pressure generating chambers 12 partitioned by a plurality of partition walls 11 are arranged in parallel in the width direction (short direction) by anisotropic etching from the other surface side. In addition, an ink supply path 14 and a communication path 15 are partitioned by a partition wall 11 on one end side in the longitudinal direction of the pressure generating chamber 12 of the flow path forming substrate 10. In addition, a communication portion 13 constituting a part of the reservoir 100 serving as an ink chamber (liquid chamber) common to the pressure generation chambers 12 is formed at one end of the communication passage 15. That is, the flow path forming substrate 10 is provided with a liquid flow path including a pressure generation chamber 12, a communication portion 13, an ink supply path 14, and a communication path 15.

  The ink supply path 14 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and has a smaller cross-sectional area than the pressure generation chamber 12.

Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive. Or a heat-welded film or the like. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], glass ceramics, silicon It consists of a single crystal substrate or stainless steel.

On the other hand, an elastic film 50 made of silicon dioxide and having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. An insulator film 55 made of zirconium oxide (ZrO ₂ ) or the like and having a thickness of, for example, about 0.4 μm is laminated. On the insulator film 55, the lower electrode film 60 having a thickness of about 0.1 to 0.5 μm and lead zirconate titanate (PZT) which is an example of a piezoelectric film are formed. For example, the piezoelectric layer 300 is formed by laminating a piezoelectric layer 70 having a thickness of about 1.1 μm and an upper electrode film 80 having a thickness of, for example, about 0.05 μm by a process described later. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In this case, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for convenience of a drive circuit and wiring. In addition, here, the piezoelectric element 300 and the diaphragm that is displaced by driving the piezoelectric element 300 are collectively referred to as an actuator device. In the above-described example, the elastic film 50 and the insulator film 55 function as a diaphragm, but only one of the elastic film 50 and the insulator film 55 may be provided as a diaphragm.

  Examples of the material of the piezoelectric layer 70 constituting the piezoelectric element 300 include a ferroelectric piezoelectric material such as lead zirconate titanate (PZT), niobium, nickel, magnesium, bismuth, yttrium, and the like. A relaxor ferroelectric or the like to which any of the above metals is added is used.

  Further, each upper electrode film 80 that is an individual electrode of the piezoelectric element 300 is provided with a lead electrode 90 made of, for example, gold (Au) or the like as a lead-out wiring drawn out from the vicinity of the end on the ink supply path 14 side. ing. The lead electrode 90 is electrically connected to the drive circuit 120 via the connection wiring 121 through a through hole 33 described later in detail.

  Further, on the flow path forming substrate 10 on which the piezoelectric element 300 is formed, a protective substrate 30 provided with a reservoir portion 31 in a region facing the communication portion 13 is bonded via an adhesive 35. As described above, the reservoir unit 31 communicates with the communication unit 13 of the flow path forming substrate 10 and constitutes the reservoir 100 serving as a common liquid chamber for the pressure generation chambers 12. Alternatively, the communication portion 13 of the flow path forming substrate 10 may be divided into a plurality of pressure generation chambers 12 and only the reservoir portion 31 may be used as the reservoir. Further, for example, only the pressure generation chamber 12 is provided in the flow path forming substrate 10, and a reservoir and a member interposed between the flow path forming substrate 10 and the protective substrate 30 (for example, the elastic film 50, the insulator film 55, etc.) An ink supply path 14 that communicates with each pressure generating chamber 12 may be provided.

  Further, the protective substrate 30 is provided with a piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 in a region facing the piezoelectric element 300. In addition, the piezoelectric element holding part 32 should just have a space of the grade which does not inhibit the motion of the piezoelectric element 300, and the said space may be sealed or may not be sealed.

  Further, a through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 32 and the reservoir portion 31 of the protective substrate 30, and the lower electrode film 60 is provided in the through hole 33. And the tip of the lead electrode 90 are exposed.

  A drive circuit 120 for driving the piezoelectric element 300 is mounted on the protective substrate 30. For example, a circuit board or a semiconductor integrated circuit (IC) can be used as the drive circuit 120. The drive circuit 120 and the lead electrode 90 are electrically connected via a connection wiring 121 made of a conductive wire such as a bonding wire.

  As the protective substrate 30, it is preferable to use a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, a ceramic material, etc. In this embodiment, the surface orientation of the same material as the flow path forming substrate 10 is used. It was formed using a (110) silicon single crystal substrate.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head I of the present embodiment, ink is taken in from an external ink supply means (not shown), filled with ink from the reservoir 100 to the nozzle opening 21, and then in accordance with a recording signal from the drive circuit 120. Then, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 to bend and deform the elastic film 50, the insulator film 55, the lower electrode film 60, and the piezoelectric layer 70. As a result, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

  Here, a manufacturing method of the ink jet recording head I will be described with reference to FIGS. 3 to 6 are cross-sectional views in the longitudinal direction of the pressure generating chamber showing the method of manufacturing the ink jet recording head, and FIG. 7 is a top view of the flow path forming substrate wafer.

  First, as shown in FIG. 3A, a flow path forming substrate wafer 110, which is a silicon wafer in which a plurality of flow path forming substrates 10 are integrally formed, is thermally oxidized in a diffusion furnace at about 1100 ° C. A silicon dioxide film 51 constituting the elastic film 50 is formed on the surface.

Next, as shown in FIG. 3B, an insulator film 55 made of zirconium oxide is formed on the elastic film 50 (silicon dioxide film 51). Specifically, after forming a zirconium (Zr) layer on the elastic film 50 (silicon dioxide film 51) by, for example, sputtering, the zirconium layer is thermally oxidized in a diffusion furnace at 500 to 1200 ° C., for example. Thus, the insulator film 55 made of zirconium oxide (ZrO ₂ ) is formed.

  Here, the thickness of the insulator film 55 which is a vibration film constituting the vibration plate is changed in the plane of the flow path forming substrate wafer 110 based on the displacement amount of the piezoelectric element 300 formed in a later step. Form. In the present embodiment, the piezoelectric element 300 is formed with higher piezoelectric characteristics (displacement characteristics) on the center A side than on the peripheral edge B side in the plane of the flow path forming substrate wafer 110, as shown in FIG. The insulator film 55 was formed so that its thickness was thin on the peripheral edge B side in the plane of the flow path forming substrate wafer 110 and thick on the center A side. The thickness of the insulator film 55 is preferably changed gradually from the peripheral edge B side toward the center A side in the plane of the flow path forming substrate wafer 110.

  Such a change in the thickness of the insulator film 55 can be achieved, for example, by adjusting the distance between the sputtering target and the flow path forming substrate wafer 110 in the sputtering apparatus when forming zirconium, or by forming the sputtering target and the flow path. This can be done by providing a shielding object such as a shielding plate between the substrate wafer 110. Since the thickness of the insulator film 55 made of zirconium oxide is defined based on the thickness of the zirconium before oxidation, the thickness of the insulator film 55 made of zirconium oxide can be changed by changing the thickness of zirconium. The thickness can be changed.

  Next, as shown in FIG. 4A, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 55, the lower electrode film 60 is patterned into a predetermined shape. The lower electrode film 60 is not limited to a laminate of platinum (Pt) and iridium (Ir), and an alloy of these may be used. Further, the lower electrode film 60 may be used as a single layer of any one of platinum (Pt) and iridium (Ir), and a metal or a metal oxide other than these materials may be used. Also good.

  Next, as shown in FIG. 4B, the piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) and the upper electrode film 80 made of, for example, iridium are formed on the entire surface of the flow path forming substrate 10. Then, the piezoelectric element 300 is formed by patterning in a region facing each pressure generating chamber 12. As a material of the piezoelectric layer 70 constituting the piezoelectric element 300, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT) or a metal such as niobium, nickel, magnesium, bismuth or yttrium is used. An added relaxor ferroelectric or the like is used. In the present embodiment, the piezoelectric layer 70 is formed by applying a so-called sol in which a metal organic material is dissolved and dispersed in a solvent, drying it to gel, and baking it at a high temperature to form a piezoelectric layer made of a metal oxide. The piezoelectric layer 70 was formed using a so-called sol-gel method to obtain 70. The method for forming the piezoelectric layer 70 is not particularly limited, and for example, a MOD method, a sputtering method, or the like may be used.

  The piezoelectric layer 70 formed in this manner has variations in piezoelectric characteristics (displacement characteristics) within the plane of the flow path forming substrate wafer 110. Specifically, the piezoelectric layer 70 has high piezoelectric characteristics on the center A side in the plane of the flow path forming substrate wafer 110 shown in FIG. 7, and the peripheral edge B side in the plane of the flow path forming substrate wafer 110. Thus, the piezoelectric characteristics are low. This is presumably because there is a bias in the temperature distribution of the heating device for firing the piezoelectric layer 70 and the difference in the base of the piezoelectric layer 70.

  For this reason, as described above, the thickness of the insulator film 55 which is a vibration film constituting the diaphragm is made thinner on the peripheral edge B side of the flow path forming substrate wafer 110 corresponding to the piezoelectric layer 70 having low piezoelectric characteristics. The center A side corresponding to the piezoelectric layer 70 having low piezoelectric characteristics is formed thick. Accordingly, the rigidity of the diaphragm (insulator film 55) on the peripheral edge B side of the flow path forming substrate wafer 110 is reduced, and the displacement characteristics of the piezoelectric layer 70 having low piezoelectric characteristics provided on the peripheral edge B side. In addition, the rigidity of the diaphragm (insulator film 55) on the center A side of the flow path forming substrate wafer 110 is increased, and the displacement characteristics of the piezoelectric layer 70 having high piezoelectric characteristics provided on the center A side are reduced. Can be made. Therefore, the displacement characteristics can be made uniform in the plane of the flow path forming substrate wafer 110 of the piezoelectric layer 70.

  As described above, the amount of displacement of the piezoelectric element 300 can be made uniform by changing the thickness of the insulator film 55 based on the piezoelectric characteristics of the piezoelectric layer 70 (the amount of displacement of the piezoelectric element 300). A plurality of ink jet recording heads I having the same displacement amount of the piezoelectric elements 300 can be simultaneously manufactured from one flow path forming substrate wafer 110. Therefore, when an ink jet recording head unit (hereinafter referred to as a head unit) is manufactured by combining a plurality of ink jet recording heads I, the ink ejection characteristics (liquid ejection characteristics) of the ink jet recording head I can be made uniform. In addition, the head unit can be printed with high accuracy and high quality.

  Further, since a single head unit can be formed by combining a plurality of ink jet recording heads I formed from one flow path forming substrate wafer 110, the yield can be improved. That is, it is not necessary to rank the ink jet recording heads I based on the displacement amount of the piezoelectric element 300 after manufacturing a plurality of ink jet recording heads I, so that the ink jet recording heads I are not excessive or insufficient for each rank.

  Further, since it is not necessary to attach another member such as an elastic member to the piezoelectric element 300 to make the displacement amount of the piezoelectric element 300 uniform, it is possible to reduce the number of parts and reduce the manufacturing cost.

  The displacement amount of the piezoelectric element 300 (piezoelectric characteristics of the piezoelectric layer 70), which serves as an index for changing the thickness of the insulator film 55, is, for example, an ink jet recording head in which the insulator film 55 is formed with a uniform thickness. Can be grasped by measuring the amount of displacement of the piezoelectric element of this sample using a laser Doppler displacement meter. Further, the amount of displacement of the piezoelectric element 300 of the ink jet recording head I formed by changing the thickness of the insulator film 55 is measured, the amount of displacement is fed back, and the ink jet recording head to be formed next is formed. By changing the thickness of the insulator film 55 of I, the displacement amount of the piezoelectric element 300 can be made uniform with higher accuracy.

  Next, as shown in FIG. 4C, after forming the lead electrode 90 made of gold (Au) over the entire surface of the flow path forming substrate wafer 110, patterning is performed for each piezoelectric element 300.

  Next, as shown in FIG. 5A, the protective substrate wafer 130 is bonded onto the flow path forming substrate wafer 110 via an adhesive 35. Here, the protective substrate wafer 130 is formed by integrally forming a plurality of protective substrates 30, and a reservoir portion 31 and a piezoelectric element holding portion 32 are formed in advance on the protective substrate wafer 130.

  Next, as shown in FIG. 5B, the flow path forming substrate wafer 110 is thinned to a predetermined thickness.

  Next, as shown in FIG. 5C, a mask film 52 is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape. Then, as shown in FIG. 6, the pressure corresponding to the piezoelectric element 300 is obtained by anisotropically etching (wet etching) the flow path forming substrate wafer 110 using an alkaline solution such as KOH through the mask film 52. A generation chamber 12 is formed.

  Thereafter, the mask film 52 on the surface of the flow path forming substrate wafer 110 is removed, and unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer 130 are cut by, for example, dicing. Remove. The nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 130. The ink jet recording head I of the present embodiment is obtained by dividing the flow path forming substrate wafer 110 and the like into a single chip size flow path forming substrate 10 as shown in FIG.

  The plurality of ink jet recording heads I formed in this manner have the same ink ejection characteristics as each ink jet recording head I, and therefore, even if the plurality of ink jet recording heads I are combined to form multiple rows, printing is possible. Accuracy and print quality are not degraded. Moreover, it is not necessary to rank the plurality of ink jet recording heads I formed simultaneously, and a plurality of ink jet recording heads can be easily combined.

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, in the first embodiment described above, the thickness of the insulator film 55 is changed within the plane of the flow path forming substrate wafer 110, but the present invention is not particularly limited thereto. The thickness of the insulator film 55 may be changed in the plane. In Embodiment 1 described above, the thickness of the insulator film 55 is formed so that the center A side gradually becomes thicker than the peripheral edge B side in the plane of the flow path forming substrate wafer 110. For example, the piezoelectric layer 70 has piezoelectric characteristics on the peripheral edge side of the flow path forming substrate wafer 110 due to a difference in the base when the piezoelectric layer 70 is formed, a temperature distribution of the heating device, or the like. When the piezoelectric properties are high and the piezoelectric properties are low on the center side, the thickness of the insulator film 55 is gradually increased on the peripheral edge B side in the plane of the flow path forming substrate wafer 110 compared to the center A side. What is necessary is just to form. That is, the thickness of the insulator film 55 may be changed based on the piezoelectric characteristics of the piezoelectric layer 70 (displacement characteristics of the piezoelectric element 300).

  In the first embodiment described above, the thickness of the insulator film 55 is changed as the vibration film constituting the diaphragm. However, the present invention is not limited to this, and for example, the elastic film 50 constituting the diaphragm is used. The thickness of both the elastic film 50 and the insulator film 55 may be changed. That is, the elastic film 50 may be a vibration film of the diaphragm, and both the elastic film 50 and the insulator film 55 may be the vibration film of the diaphragm. In the first embodiment described above, changing the thickness of the insulator film 55 made of zirconium oxide makes it easier and more accurate than changing the thickness of the relatively thin elastic film 50. The thickness can be controlled. Of course, in the first embodiment described above, an example in which the diaphragm is constituted by the elastic film 50 made of silicon dioxide and the insulator film 55 made of zirconium oxide has been shown. It is not limited.

  Further, in Embodiment 1 described above, the zirconium oxide is formed by sputtering, and then the zirconium is thermally oxidized to form the insulator film 55 made of zirconium oxide. It is not limited to this, For example, you may form by a vapor deposition method, CVD method, etc.

  Furthermore, in Embodiment 1 described above, the silicon single crystal substrate is exemplified as the flow path forming substrate 10, but the present invention is not particularly limited thereto, and the present invention is also effective in, for example, an SOI substrate, a glass substrate, an MgO substrate, and the like. .

  In the first embodiment described above, the ink jet recording head I has been described as an example of the liquid ejecting head. However, the present invention broadly targets all liquid ejecting heads and ejects liquids other than ink. Of course, the present invention can also be applied to a method of manufacturing a liquid jet head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a top view illustrating the recording head manufacturing method according to the first embodiment.

Explanation of symbols

  I ink jet recording head (liquid ejecting head), 10 flow path forming substrate, 12 pressure generating chamber, 13 communication portion, 14 ink supply path, 15 communication passage, 16 recess, 20 nozzle plate, 21 nozzle opening, 30 protective substrate, 31 Reservoir section, 32 Piezoelectric element holding section, 40 Compliance substrate, 50 Elastic film, 55 Insulator film, 60 Lower electrode film, 70 Piezoelectric layer, 80 Upper electrode film, 90 Lead electrode, 100 Reservoir, 120 Drive circuit, 121 Connection wiring, 300 Piezoelectric element

Claims (7)

A flow path forming substrate provided with a pressure generating chamber communicating with the nozzle opening, and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided on one surface side of the flow path forming substrate via a vibration plate; A method of manufacturing a liquid jet head comprising:
Forming the vibration plate on one surface side of the flow path forming substrate, and forming a vibration film constituting the vibration plate by changing a thickness based on a displacement amount of the piezoelectric element; and the vibration A method of manufacturing a liquid jet head, comprising: forming the piezoelectric element on a plate; and forming the pressure generating chamber on the flow path forming substrate.   The vibration plate includes an elastic film provided on the flow path forming substrate and an insulator film provided on the elastic film, and the vibration film is at least one of the elastic film and the insulator film. The method of manufacturing a liquid jet head according to claim 1, wherein:   The method of manufacturing a liquid jet head according to claim 2, wherein the vibration film is the insulator film made of zirconium oxide.   After the step of forming the pressure generating chamber, the step of measuring the displacement amount of the piezoelectric element, and feeding back the measured displacement amount of the piezoelectric element to change the thickness of the vibration film. The method for manufacturing a liquid jet head according to claim 1.   In the step of forming the vibration film, the thickness of the vibration film formed in the region where the displacement amount of the piezoelectric element is large is equal to the thickness of the vibration film formed in the region where the displacement amount of the piezoelectric element is small. The method of manufacturing a liquid jet head according to claim 1, wherein the liquid jet head is formed so as to be thicker.   After the diaphragm, the piezoelectric element, and the pressure generating chamber are formed on the flow path forming substrate wafer in which a plurality of the flow path forming substrates are integrally formed, the flow path forming substrate wafer is moved to the plurality of flow paths. The method of manufacturing a liquid jet head according to claim 1, wherein the liquid jet head is divided into path formation substrates.   In the step of forming the vibration film, the vibration film is formed so that the thickness of the vibration film is gradually thicker on the center side than on the peripheral edge side in the plane of the flow path forming substrate wafer. A method of manufacturing a liquid jet head according to claim 6.

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