JP2018153970A - Liquid discharge head and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a discharge port, a pressure chamber and a cavity from positionally deviating.SOLUTION: The liquid discharge head has a first silicon layer 117, a second silicon layer 119, and an intermediate layer 118 made of an inorganic material arranged between the first silicon layer 117 and the second silicon layer 119. The first silicon layer 117 comprises a first recessed part 150 which exposes the intermediate layer 118 partially and forms a pressure chamber 130 for storing liquid. The second silicon layer 119 comprises a discharge port 120 through which liquid is discharged and a second recessed part 121 which exposes the intermediate layer 118 partially. The intermediate layer 118 has: an SOI substrate 116 having an opening through which the discharge port 120 is communicated with the pressure chamber 130; a squeezing plate 131 which covers the first recessed part 150 of the first silicon layer 117 and comprises a squeezing opening 132 through which liquid is flown into the pressure chamber 130; and a piezoelectric element 122 provided in the exposed intermediate layer 118 of the second recessed part 121.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid discharge head and a manufacturing method thereof, and more particularly to a liquid discharge head using a piezoelectric element and a manufacturing method thereof.

2. Description of the Related Art An ink jet apparatus that performs recording by discharging ink onto a recording medium includes a liquid discharge head in which a large number of discharge ports are arranged on a substrate at high density in order to perform high-definition recording. A liquid discharge head using a piezoelectric element includes a pressure chamber, a diaphragm that forms part of the wall surface of the pressure chamber, a piezoelectric element that is provided on the opposite side of the pressure chamber of the diaphragm, and a discharge port that communicates with the pressure chamber. It is configured. This type of liquid ejection head includes an ejection port forming substrate on which ejection ports are formed, a pressure chamber substrate on which a pressure chamber, a vibration plate, and a piezoelectric element are formed, and a cavity substrate on which a cavity for housing the piezoelectric element is formed. Are bonded together with an adhesive or the like.
In Patent Document 1, a discharge port forming substrate in which a discharge port and a cavity are integrally formed, a diaphragm in which a piezoelectric element is integrally formed, and a pressure chamber substrate in which a pressure chamber is formed are bonded together. A liquid ejection head is disclosed. The piezoelectric element is formed on the opposite side of the pressure chamber of the diaphragm. Patent Document 2 discloses a technique for forming a pressure chamber and a cavity by etching a silicon layer of an SOI (silicon on insulator) substrate in which a SiO ₂ layer is inserted into a silicon layer.

JP 2002-264336 A JP 2004-237448 A

  Generally, when joining two members, it is very difficult to align the relative positions of the two members, and a certain positional deviation is inevitable. In particular, when a liquid adhesive is used, misalignment may increase due to slippage after alignment. If a displacement occurs when the discharge port forming substrate is bonded to the pressure chamber substrate, the position of the discharge port with respect to the pressure chamber is shifted. If a displacement occurs when the cavity substrates are joined, the position of the cavity that defines the movable range of the diaphragm is displaced. In recent liquid ejection heads, the width of the pressure chamber has been reduced to several tens of μm due to higher density of ejection ports. In such a liquid discharge head, if the position of the discharge port or the cavity is slightly shifted, the discharge performance may vary greatly.

In the liquid discharge head described in Patent Document 1, the discharge port and the cavity are formed in the discharge port forming substrate, and the discharge port forming substrate also serves as the cavity substrate. Therefore, it is not necessary to join the discharge port forming substrate and the cavity substrate separately, and the manufacturing process can be simplified. However, if a displacement occurs when the discharge port forming substrate and the pressure chamber substrate are joined, both the discharge port and the cavity are displaced from the pressure chamber, and the discharge performance changes greatly. In addition, since the discharge port forming substrate and the pressure chamber substrate are bonded to the vibration plate with an adhesive, the discharge port forming substrate may be peeled off due to the influence of the ink or the piezoelectric element may be broken.
In the liquid ejection head described in Patent Document 2, since the pressure chamber and the cavity are formed on the SOI substrate that is integrally formed in advance, the positional deviation between the pressure chamber and the cavity can be reduced. However, in the step of bonding the discharge port forming substrate to the pressure chamber substrate, it is necessary to align the discharge port forming substrate, and the position of the discharge port may be shifted from the pressure chamber.

  An object of the present invention is to provide a liquid discharge head in which displacement of the discharge port, the pressure chamber, and the cavity is suppressed, and a method for manufacturing the liquid discharge head.

  The liquid discharge head according to the present invention includes a first silicon layer, a second silicon layer, and an intermediate layer made of an inorganic material disposed between the first silicon layer and the second silicon layer. The first silicon layer includes a first recess that partially exposes the intermediate layer and forms a pressure chamber for storing liquid, and the second silicon layer includes a discharge port for discharging the liquid, and the intermediate layer. A second recess that is partially exposed; the intermediate layer covers an SOI substrate having an opening that communicates the discharge port with the pressure chamber; and the first recess of the first silicon layer covers the liquid into the pressure chamber. A diaphragm plate having a diaphragm opening to be introduced and a piezoelectric element provided in the exposed intermediate layer of the second recess.

  According to the present invention, since the pressure chamber, the discharge port, and the second recess functioning as a cavity are formed on one SOI substrate, it is not necessary to bond a plurality of substrates. The displacement of the pressure chamber, the discharge port, and the cavity due to the above does not occur. For this reason, according to the present invention, it is possible to provide a liquid discharge head that can suppress the positional deviation of the discharge port, the pressure chamber, and the cavity and has stable discharge performance.

It is a schematic block diagram of the inkjet apparatus using the liquid discharge head of this invention. FIG. 2 is a plan view and a cross-sectional view of a liquid ejection head according to a first embodiment. FIG. 3 is a cross-sectional view of a main part of the liquid discharge head shown in FIG. 2. It is the top view seen from the A direction of FIG. FIG. 4 is a cross-sectional view of a main part of a modification of the liquid ejection head shown in FIG. 3. FIG. 4 is a cross-sectional view of a main part of a modification of the liquid ejection head shown in FIG. 3. FIG. 4 is a cross-sectional view of a main part of a modification of the liquid ejection head shown in FIG. 3. FIG. 4 is a cross-sectional view showing a method for manufacturing the liquid ejection head shown in FIG. 3. FIG. 4 is a cross-sectional view showing a method for manufacturing the liquid ejection head shown in FIG. 3. FIG. 4 is a cross-sectional view showing a method for manufacturing the liquid ejection head shown in FIG. 3. It is sectional drawing which shows the procedure of a water repellent process. FIG. 6 is a plan view of a liquid ejection head according to a second embodiment. It is a principal part top view of the liquid discharge head shown in FIG. FIG. 10 is a cross-sectional view of a main part of a liquid ejection head according to a third embodiment. FIG. 15 is a plan view of main parts of the liquid ejection head shown in FIG. 14.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. The following embodiments relate to an ink jet head that forms characters and images by ejecting ink onto a recording medium such as paper. The present invention is widely applied to liquid ejecting heads using piezoelectric elements that eject liquids other than ink. can do.

(First embodiment)
FIG. 1 shows a schematic configuration of an ink jet apparatus using a liquid discharge head according to the first embodiment of the present invention. A recording sheet 101 as a recording medium is fed in the direction of an arrow by a paper feed roller 102 and recorded on a platen 103. The ink jet apparatus includes four sets of liquid discharge head units 104, and each liquid discharge head unit 104 discharges cyan, magenta, yellow, and black inks. Each liquid discharge head unit 104 is connected to a drive unit 105 that electrically drives a piezoelectric element described later. The drive unit 105 generates a drive signal for driving the piezoelectric element based on an image signal or the like sent from the controller 106.

  2A is a plan view of the liquid discharge head unit 104 viewed from the discharge port surface side where the discharge ports are formed, and FIG. 2B is a plan view of the liquid discharge head unit 104 taken along line A- It is sectional drawing cut by A line. As shown in FIG. 2A, a plurality of liquid discharge heads 107 are arranged in a staggered manner on the chip frame 108 of the liquid discharge head unit 104. Each liquid discharge head 107 is formed with two discharge port arrays 110, and 500 discharge ports are arranged in each discharge port array 110 at a density of 300 dpi. The two ejection port arrays 110 formed in one liquid ejection head 107 are shifted from each other by a half pitch (about 42.3 μm) of 300 dpi. Therefore, each liquid discharge head 107 is provided with a total of 1000 discharge ports, and 600 dpi recording is possible. As shown in FIG. 2B, the liquid discharge head 107 is fitted and held in a frame provided on the chip frame 108. The wiring drawn from each piezoelectric element of the liquid discharge head 107 is drawn in the + Y direction or -Y direction in FIG. The wiring is electrically connected to the lead electrode 113 formed on the chip frame 108 by wire bonding 112 at the end of the liquid discharge head 107. The lead electrode 113 is drawn out to the back side (−Z side) of the chip frame 108 through the through electrode 114 formed in the chip frame 108, and is connected to the controller 106 through the flexible cable 115.

  The liquid ejection head 107 can be connected to the flexible cable 115 on the surface on the + Z side without using the through electrode 114. Alternatively, the lead electrode may be patterned in advance on the surface of the chip frame 108 on the −Z side and the frame that holds the liquid discharge head 107, and the electrode pad of the liquid discharge head 107 may be in direct contact with the lead electrode. According to this configuration, the liquid discharge head 107 can be electrically connected to the chip frame 108 without using wire bonding.

FIG. 3 shows a cross section of the main part of the liquid discharge head. The liquid discharge head 107 includes an SOI substrate 116, a diaphragm plate 131 provided on one surface of the SOI substrate 116, and a piezoelectric element 122 provided on the other surface of the SOI substrate 116. The SOI substrate 116 includes a first silicon layer 117, a second silicon layer 119, and an intermediate layer 118 disposed between the first silicon layer 117 and the second silicon layer 119. The first surface 118 a of the intermediate layer 118 is in contact with the first silicon layer 117, and the second surface 118 b which is the back surface of the first surface 118 a is in contact with the second silicon layer 119. The first silicon layer 117 and the second silicon layer 119 are formed of single crystal silicon, but may be formed of polysilicon. The intermediate layer 118 is made of an inorganic material layer, and is formed of SiO ₂ in this embodiment. The intermediate layer 118 can be formed of SiN, or can be formed of a stacked structure of a SiN layer and a SiO ₂ layer.

  The first silicon layer 117 is formed with a first recess 150 that opens toward the aperture plate 131 and forms a space of the pressure chamber 130. The first recess 150 reaches the intermediate layer 118 and exposes a part of the first surface 118 a of the intermediate layer 118. The first silicon layer 117, together with the first surface 118a of the intermediate layer 118 and the diaphragm plate 131, forms a pressure chamber 130 that stores ink. The second silicon layer 119 is formed with a discharge port 120 that communicates with the pressure chamber 130 and discharges ink, and a second recess 121 that is adjacent to the discharge port 120. The second recess 121 reaches the intermediate layer 118 and exposes a part of the second surface 118b of the intermediate layer 118. The discharge port 120 and the first and second recesses 150 and 121 are formed by silicon etching using the intermediate layer 118 as an etch stop layer, as will be described later.

  The intermediate layer 118 serves as a support structure for the piezoelectric element 122 and also functions as the diaphragm 123 of the piezoelectric element 122. The first surface 118 a of the intermediate layer 118 facing the pressure chamber 130 defines a part of the pressure chamber 130. A portion of the intermediate layer 118 that faces the discharge port 120 is a through hole 118 c that allows the discharge port 120 to communicate with the pressure chamber 130, thereby enabling ink to be discharged from the discharge port 120.

  The diaphragm plate 131 is formed with a diaphragm opening 132 that communicates with the pressure chamber 130 and allows ink to flow into the pressure chamber 130. The pressure chamber 130 communicates with a common liquid chamber (not shown) to which ink is supplied through a throttle opening 132. The aperture plate 131 faces the first recess 150 of the first silicon layer 117.

  A piezoelectric element 122 is provided in the second recess 121. The piezoelectric element 122 includes a lower electrode 124 which is a common electrode, a piezoelectric body 125 made of PZT (lead zirconate titanate), an upper electrode 126 which is an individual electrode, a piezoelectric body 125 and a pair of upper and lower electrodes 124 and 126. And a protective film 127 for covering. A contact hole 128 is formed in the protective film 127, and the upper electrode 126 is connected to the individual electrode wiring 129 through the contact hole 128. The lower electrode 124 and the individual electrode wiring 129 are insulated by a protective film 127.

  FIG. 4 is a plan view showing wiring between the second recess 121 and the piezoelectric element 122. In FIG. 4, illustration of the protective film 127 is omitted. The second recess 121 accommodates each piezoelectric element 122 and extends in parallel with the short side direction (Y direction) of the piezoelectric element 122, and the X direction along the long side of the SOI substrate 116. And a lateral recess 152 where the individual longitudinal grooves 151 meet.

  A common electrode lead-out wiring 153 is connected to the lower electrode 124, which is a common electrode, and a common electrode electrode pad 133 is connected to the common electrode lead-out wiring 153. The lower electrode 124 and the common electrode lead-out wiring 153 are structurally identical, and are collectively formed by patterning a metal film. Here, for convenience, a portion immediately below the piezoelectric body 125 is referred to as a lower electrode 124, and a portion other than the lower electrode 124 is referred to as a lead wiring 153. The common electrode lead-out wiring 153 is formed substantially in accordance with the shape of the second recess 121. The lead-out wiring 153 includes a plurality of first portions 153a extending in the Y direction through the vertical groove 151, and a second portion 153b extending in the X direction through the horizontal recess 152 by joining the plurality of first portions 153a. It has become. The electrode pad 133 for the common electrode is provided at the end of the second portion 153b in the X direction. The protective film 127 is removed and the electrode pad 133 is exposed in the vicinity of the electrode pad 133 for the common electrode so that the lead electrode 113 can be electrically connected.

  The individual electrode wiring 129 that is a lead-out wiring connected to the upper electrode 126 passes over the protective film 127 and terminates at the Y-direction end of the lateral recess 152 of the second recess 121, and there is an electrode pad for the individual electrode there. 134 is formed. The individual electrode wiring 129 is formed by patterning a metal film formed on the protective film 127.

  As described above, one common electrode electrode pad 133 and a plurality of individual electrode electrode pads 134 are arranged on a part of the outer peripheral portion of the SOI substrate 116. The second recess 121 exposes a part of the outer periphery of the intermediate layer 118, and the electrode pads 133 and 134 are provided on the exposed outer periphery of the intermediate layer 118. The second silicon layer 119 is removed from the outer peripheral portion where the electrode pads 133 and 134 are provided, and electrical connection (wire bonding) between the electrode pads 133 and 134 and the lead electrode 113 can be easily performed.

  In the liquid discharge head 107 of this embodiment, since the discharge port 120 and the pressure chamber 130 are formed on one SOI substrate 116, the displacement of the discharge port 120 and the pressure chamber 130 due to the bonding of the substrates occurs in principle. Absent. In addition, since the second recess 121 corresponding to the conventional cavity that defines the movable range of the diaphragm 123 is also formed in the SOI substrate 116, the movable range of the diaphragm 123 and the discharge port 120 or the pressure due to the bonding of the substrates. In principle, displacement from the chamber 130 does not occur. For this reason, according to the present invention, it is possible to provide the liquid discharge head 107 having stable discharge performance.

  In the above-described embodiment, the lower electrode 124 is a common electrode and the upper electrode 126 is an individual electrode. However, the lower electrode 124 may be an individual electrode and the upper electrode 126 may be a common electrode. In this case, a plurality of individual electrode electrode pads connected to the plurality of lower electrodes 124 and one common electrode electrode pad connected to the upper electrode 126 are provided on the outer periphery of the second recess 121. It is done.

  FIG. 5 is a view similar to FIG. 3 showing a modification of the liquid discharge head 107 of the present embodiment. In this modification, a lid member 135 that covers the second recess 121 is provided. The lid member 135 completely covers the second recess 121 and is sealed to the second silicon layer 119 with an adhesive or the like. An opening 136 is formed in a portion corresponding to the ejection port 120 of the lid member 135 so as not to hinder ink ejection. By providing the lid member 135, the piezoelectric element 122 can be protected from water vapor in the atmosphere and minute ink droplets (so-called mist) that float without landing on the recording medium when ejected from the ejection port 120. . It is desirable that the periphery of the discharge port 120 inside the opening 136 is water-repellent.

  Although illustration is omitted, the lid member 135 may be provided with at least one of a lead wire connected to the piezoelectric element 122 and an electrode pad connected to the lead wire. For example, the individual electrode wiring 129 can be routed along the second recess 121 and can be connected to the wiring formed on the surface of the lid member 135 facing the second recess 121. It is also possible to form wirings and electrode pads on the surface of the lid member 135 facing the second recess 121, and connect the individual electrode wirings 129 and the electrode pads with bumps. The wiring formed on the lid member 135 can be drawn out to the outside of the lid member 135 along the lid member 135. Similarly, the lead-out wiring for the common electrode is connected to the electrode pad formed on the surface facing the second recess 121 of the lid member 135 with a bump, and the wiring formed on the lid member 135 is connected to the outside of the lid member 135. Can be pulled out.

  FIG. 6 is a view similar to FIG. 3 showing another modification of the liquid discharge head 107 of the present embodiment. In this modification, the lead-out wiring for the individual electrode extends through the second recess 121 and penetrates the protective film 127, the intermediate layer 118 (vibrating plate 123), and the first silicon layer 117. A portion of the lead-out wiring for the individual electrode that penetrates the protective film 127, the intermediate layer 118, and the first silicon layer 117 is formed as a contact hole 137. Although not shown, the lead-out wiring further extends on the surface of the first silicon layer 117 facing the diaphragm plate 131, that is, the boundary surface with the diaphragm plate 131. The first silicon layer 117 protrudes from the diaphragm plate 131, and an electrode pad connected to the lead-out wiring is formed on the protruding portion of the first silicon layer 117.

  Similarly, a common electrode lead-out wiring 153 passes through the protective film 127, the intermediate layer 118 (the diaphragm 123), and the first silicon layer 117. Similarly to the lead-out wiring for the individual electrodes, the lead-out wiring 153 extends on the surface of the first silicon layer 117 facing the diaphragm plate 131, that is, the boundary surface with the diaphragm plate 131, and is connected to the electrode pad with the same configuration. Is done. These electrode pads are connected to the controller 106 via the flexible cable 115. According to this configuration, the electrode pad can be directly connected to the flexible cable 115 without using the lead electrode 113 and the through electrode 114. For this reason, the structure of the electrical connection part of the piezoelectric element 122 and the flexible cable 115 becomes simple.

  Instead of the above-described modification, the lead wiring for the individual electrode and the common electrode may be formed on the surface of the diaphragm plate 131 that faces the first silicon layer 117. The diaphragm plate 131 projects beyond the first silicon layer 117, and an electrode pad is formed on the projecting portion of the diaphragm plate 131.

  FIG. 7 is a view similar to FIG. 3 showing another modification of the liquid ejection head 107 of the present embodiment. In this modification, a CMOS switch 139 that functions as a switch for switching on / off of energization to the piezoelectric element 122 is provided inside the diaphragm plate 131. That is, in this modification, the CMOS substrate also serves as the diaphragm plate 131. The lead-out wiring for the individual electrode connected to the piezoelectric element 122 extends through the second recess 121, penetrates the protective film 127, the intermediate layer 118 (vibrating plate 123), and the first silicon layer 117, and the inside of the diaphragm plate 131. Is extended to the CMOS switch 139. Similarly, the common electrode lead-out wiring 153 connected to the piezoelectric element 122 passes through the protective film 127, the intermediate layer 118 (the diaphragm 123), and the first silicon layer 117, and the inside of the diaphragm plate 131 is connected to the CMOS switch. 139. In this modification, since the CMOS switch 139 is formed on the diaphragm plate 131, the number of wires between the liquid discharge head 107 and the controller 106 can be greatly reduced, and the manufacturing cost of the ink jet apparatus can be greatly reduced. it can.

Next, a method for manufacturing the liquid discharge head 107 shown in FIGS.
FIG. 8 shows a process flow diagram of the step of forming the second recess 121 in the SOI substrate 116. First, as shown in FIG. 8A, the first silicon layer 117, the second silicon layer 119, and the inorganic material disposed between the first silicon layer 117 and the second silicon layer 119. An SOI substrate 116 is prepared. The intermediate layer 118 is in physical contact with the first silicon layer 117 and the second silicon layer 119, and between the intermediate layer 118 and the first silicon layer 117 and between the intermediate layer 118 and the second silicon layer 117. A layer such as an adhesive layer is not interposed between the first layer 119 and the second layer 119. Next, as shown in FIG. 8B, a resist mask 140 is formed on the second silicon layer 119 of the SOI substrate 116 (device layer of the SOI substrate 116) and patterned by photolithography. Next, as shown in FIG. 8C, the second recess 121 is formed by dry etching using the intermediate layer 118 as an etch stop layer. As a result, the intermediate layer 118 is exposed in the second recess 121. Although not shown, a through hole corresponding to the discharge port 120 is also formed in the second silicon layer 119 at the same time. Further, the portion of the intermediate layer 118 corresponding to the discharge port 120 is also removed by etching. Thereafter, as shown in FIG. 8D, the resist mask 140 is removed. Thus, the second recess 121 and the discharge port 120 are formed in the SOI substrate 116.

FIG. 9 shows a process flow diagram of the process of forming the piezoelectric element 122 on the SOI substrate 116. First, as shown in FIG. 9A, a layer 141 serving as a material for the lower electrode 124 is formed in the second recess 121 by sputtering. In this embodiment, a TiO ₂ layer, a Ti layer, and a Pt layer are formed in this order. Subsequently, as shown in FIG. 9B, a resist mask 142 is formed, and as shown in FIG. 9C, the layer 141 is dry-etched to form the lower electrode 124. Next, as shown in FIG. 9D, a PZT layer 143 that is a material of the piezoelectric body 125 and a Pt layer 144 that is a material of the upper electrode 126 are formed by sputtering. The PZT layer 143 can also be formed by a sol-gel method or spray coating. Next, as shown in FIG. 9E, a resist mask 145 is formed, and as shown in FIG. 9F, the PZT layer 143 and the Pt layer 144 are dry-etched to form the piezoelectric body 125 and the upper electrode 126. Form. After removing the resist mask 145, as shown in FIG. 9G, a SiO ₂ layer 146 serving as a protective film 127 covering the lower electrode 124, the piezoelectric body 125, and the upper electrode 126 is formed by sputtering. Subsequently, as shown in FIG. 9H, a resist mask 147 is formed. At this time, the resist mask 147 is not formed in a portion corresponding to the contact hole 128 formed in the protective film 127. Although illustration is omitted, the SiO ₂ layer 146 in the ejection port 120 is also left as a protective film against ink. Next, as shown in FIG. 9I, a protective film 127 provided with contact holes 128 is formed by dry etching. Then, as shown in FIG. 9J, the individual electrode wiring 129 is formed by sputtering. Thus, the piezoelectric element 122 is formed on the exposed intermediate layer 118 of the second recess 121.

  FIG. 10 shows a process flow diagram of the process of forming the pressure chamber 130 and the diaphragm plate 131. First, in order to improve handling properties, a support substrate 148 is bonded to the second silicon substrate 119 as shown in FIG. Next, as shown in FIG. 10B, the first silicon layer 117 is polished so that the first recess 150 (pressure chamber 130) has a desired height. Next, as shown in FIG. 10C, a resist mask is patterned on the polished first silicon layer 117 (not shown), and the pressure chamber 130 is formed by dry etching using the intermediate layer 118 as an etching stop layer. The first recess 150 is formed. Thereafter, the resist mask is removed. A portion of the second surface 118b of the intermediate layer 118 is exposed by the first recess 150. Thereafter, as shown in FIG. 10D, the diaphragm plate 131 in which the diaphragm opening 132 is formed in advance is joined to the first silicon layer 117 so that the diaphragm opening 132 communicates with the first recess 150. Through the above steps, the pressure chamber 130 and the diaphragm 123 are formed. Although not shown, the diaphragm plate 131 is subsequently joined to a manifold in which a common liquid chamber or the like is formed. Thus, the liquid discharge head 107 is completed. If necessary, the lid member 135 is bonded to the first silicon layer 117 in a subsequent process.

The periphery of the discharge port 120 on the discharge port surface is preferably subjected to water repellent treatment in order to prevent the discharge from becoming unstable due to ink wetting. However, since the discharge becomes unstable when the inside of the discharge port 120 is subjected to water repellent treatment, it is desirable that only the discharge port surface be subjected to water repellent treatment. FIG. 11 shows a process flow diagram in the case of performing water-repellent treatment on the discharge port surface. FIG. 11A corresponds to the state where the individual electrode wiring 129 is formed in FIG. As shown in FIG. 11B, a water repellent material 149 is applied to the entire surface of the second silicon layer 119. The water repellent material 149 also enters the discharge port 120. Subsequently, as shown in FIG. 11C, a support substrate 148 is bonded to the second silicon layer 119, and the first silicon layer 117 is first etched by dry etching as shown in FIG. The recess 150 is formed. Next, as shown in FIG. 11E, the water repellent material 149 in the discharge port 120 is removed by O ₂ plasma ashing. Next, as shown in FIG. 11F, the diaphragm plate 131 is joined and the support substrate 148 is removed. According to such a method for manufacturing the liquid discharge head 107, it is possible to manufacture the liquid discharge head 107 in which the water repellent treatment is not performed in the discharge port 120 while the water repellent treatment is performed on the discharge port surface.

(Second Embodiment)
Next, the liquid ejection head 207 of the second embodiment will be described. The description of the same configuration as that of the first embodiment is omitted.
FIG. 12 is a view similar to FIG. 2A when the liquid discharge head 207 is viewed from the discharge port surface side where the discharge ports are formed. The liquid discharge head 207 of this embodiment is provided with four discharge port arrays 210. In each discharge port array 210, 500 discharge ports are arranged at a density of 300 dpi. The four discharge port arrays 210 are shifted from each other by a pitch of 1/4 (about 21.2 μm) of 300 dpi. Therefore, the liquid ejection head 207 is provided with a total of 2000 ejection ports 120 and can perform 1200 dpi recording.

  FIG. 13 is a diagram illustrating the wiring between the second recess 221 and the liquid ejection head 207. In FIG. 13, illustration of the protective film is omitted. A plurality of piezoelectric elements 222, a plurality of lead wirings (individual electrode wirings) 229 connected to each piezoelectric element 222 and led out in the same direction, and a plurality of electrode pads 234 respectively connected to the plurality of lead wirings 229 It is provided in the recess 221. The common electrode lead-out wiring 253 is provided so as to circulate along two rows of piezoelectric elements 222, and is connected to the electrode pad 233 at the end of the liquid ejection head 207 in the X direction. In the present embodiment, the second silicon layer 219 is removed except for the periphery of the ejection port 220 and the end of the liquid ejection head 207 in the X direction. That is, there is no groove for accommodating the individual piezoelectric elements 222 as in the first embodiment, and the entire area excluding the periphery of the discharge port 220 and the end portion in the X direction of the liquid discharge head 207 is the second recess 221. It has become. In this embodiment, since the range of the 2nd recessed part 221 is expanded rather than 1st Embodiment, a wide wiring space is securable. Therefore, wiring can be easily performed even in the case of a high discharge port density of 1200 dpi (300 dpi × 4 rows).

(Third embodiment)
Next, the liquid discharge head 307 of the third embodiment will be described. The description of the same configuration as in the first and second embodiments is omitted.
FIG. 14 is a view similar to FIG. 3 showing the main part of the liquid discharge head 307. FIG. 15 is a diagram showing wiring between the second recess 321 and the liquid discharge head 307. In FIG. 15, the protective film is not shown. In the present embodiment, each of the plurality of piezoelectric elements 322 is provided in a separate second recess 321. Specifically, wet etching is performed with KOH from the (100) surface, which is the surface of the second silicon layer 319, to form the inclined side wall 351 of the second recess 321 composed of the (111) surface. Lead wires (individual electrode wires) 329 connected to each piezoelectric element 322 are led in the same direction as the other lead wires 329. The individual electrode wiring 329 extends through the second recess 321 provided individually for each piezoelectric element 322, and extends from the surface of the second silicon layer 319 outside the separately provided second recess 321. That is, in this embodiment, the individual electrode wiring 329 is formed on the side wall 351 that forms the second recess 321. Since the side wall 351 is inclined as described above, disconnection at the edge of the individual electrode wiring 329 is difficult to occur. The common electrode lead-out wiring 353 is provided so as to circulate along two rows of piezoelectric elements 322, and is connected to the electrode pad 333 at the end of the liquid ejection head 307 in the X direction.

  In this embodiment, the piezoelectric element 322 is completely surrounded by the side wall 351 of the second recess 321. Since the diaphragm 323 is strongly restrained from both sides by the side wall of the pressure chamber 330 formed in the first silicon layer 317 and the side wall 351 of the second recess 321 of the second silicon layer 319, the vibration plate 323 vibrates. The displacement region of the plate 323 is clearly defined, and the discharge characteristics are stabilized. The lead wires for the common electrode and the individual electrodes are drawn to the upper surface of the second silicon layer 119 through the side wall 351 of the second recess 321. Also in this embodiment, since a wide space on the second silicon layer 319 can be used for wiring, wiring can be easily performed even in the case of a high discharge port density of 1200 dpi or more.

  In FIG. 15, the lower electrode 324 and the individual electrode wiring 329 in the cavity are patterned in a predetermined shape, but these are not necessarily patterned. That is, the lower electrode 324 and the individual electrode wiring 329 may be formed on the entire bottom surface and side wall of the second recess 321, and in this way, the lower electrode 324 and the individual electrode wiring 329 are insulated by the protective film. The

  Note that the liquid discharge head of the present invention is not limited to the SOI substrate, and is generally disposed between the first layer, the second layer, the first layer, and the second layer, And an intermediate layer in physical contact with the second layer. The first layer includes a first recess that partially exposes the intermediate layer and forms a pressure chamber that stores liquid, and the second layer includes a discharge port from which liquid is discharged and the intermediate layer partially The intermediate layer has a through hole that communicates the discharge port with the pressure chamber. The liquid discharge head is further provided in an exposed intermediate layer of a diaphragm plate that covers the first recess of the first silicon layer and has a throttle opening for allowing the liquid to flow into the pressure chamber, and the second recess. And a piezoelectric element.

116 SOI substrate 117 First silicon layer 118 Intermediate layer 119 Second silicon layer 120 Discharge port 121 Second recess 122 Piezoelectric element 130 Pressure chamber 131 Diaphragm plate 150 First recess

Claims (23)

A first silicon layer; a second silicon layer; and an intermediate layer made of an inorganic material disposed between the first silicon layer and the second silicon layer. The layer includes a first recess that partially exposes the intermediate layer and forms a pressure chamber for storing liquid, and the second silicon layer includes a discharge port from which liquid is discharged and the intermediate layer partially An SOI substrate having an opening that allows the discharge port to communicate with the pressure chamber;
A diaphragm plate having a diaphragm opening that covers the first recess of the first silicon layer and allows liquid to flow into the pressure chamber;
And a piezoelectric element provided in the exposed intermediate layer of the second recess.   The lead wire connected to the piezoelectric element and an electrode pad connected to the lead wire, wherein the lead wire and the electrode pad are provided in the second recess. Liquid discharge head.   3. The liquid ejection head according to claim 2, wherein the second recess exposes a part of the outer peripheral portion of the intermediate layer, and the electrode pad is provided in the outer peripheral portion of the intermediate layer exposed. .   A lead wire connected to the piezoelectric element; and an electrode pad connected to the lead wire; the electrode pad is provided in the vicinity of a boundary surface between the first silicon layer and the diaphragm plate; 2. The liquid ejection head according to claim 1, wherein the lead-out wiring extends through the second recess, penetrates through the first silicon layer, and extends through the boundary surface to the pad.   A lead wire connected to the piezoelectric element; and a CMOS switch connected to the lead wire, wherein the CMOS switch is provided inside the diaphragm plate, and the lead wire extends through the second recess. 2. The liquid ejection head according to claim 1, wherein the liquid ejection head penetrates the first silicon layer and extends to the CMOS switch inside the aperture plate.   A plurality of piezoelectric elements; a plurality of lead wires connected to the respective piezoelectric elements and led out in the same direction; and a plurality of electrode pads respectively connected to the plurality of lead wires. 2. The liquid ejection head according to claim 1, wherein the plurality of lead-out wirings and the plurality of electrode pads are provided in one second recess.   A plurality of piezoelectric elements, and a plurality of lead wires connected to each piezoelectric element and led out in the same direction, and each of the plurality of piezoelectric elements is provided in a separate second recess. The liquid discharge head according to claim 1.   8. The liquid ejection head according to claim 7, wherein the plurality of lead wirings extend through the individual second recesses, and extend on a surface of the second silicon layer outside the individual second recesses.   The liquid ejection head according to claim 1, further comprising a lid member that covers the second recess.   The liquid ejection head according to claim 9, wherein at least one of a lead wiring connected to the piezoelectric element and an electrode pad connected to the lead wiring is formed on the lid member.   11. The piezoelectric element according to claim 1, comprising: a piezoelectric body; a pair of electrodes sandwiching the piezoelectric body; and a protective film covering the piezoelectric body and the pair of electrodes. Liquid discharge head. The intermediate layer on the second layer of the substrate comprising: a first layer; a second layer; and an intermediate layer disposed between the first layer and the second layer. Forming a second recess that is partially exposed;
Providing a piezoelectric element on the exposed intermediate layer of the second recess;
Forming a discharge port through which the liquid is discharged in the second layer, and forming a through hole communicating with the discharge port in the intermediate layer;
Forming a first recess in the first layer that communicates with the through hole and partially exposes the intermediate layer;
A diaphragm plate having a diaphragm aperture is defined by the first silicon layer, the intermediate layer, and the diaphragm plate by bonding the diaphragm aperture to the substrate so that the diaphragm aperture communicates with the first recess. Forming a pressure chamber for storing liquid, and a method for manufacturing a liquid discharge head.   13. The method of manufacturing a liquid discharge head according to claim 12, wherein the substrate is an SOI substrate in which the first and second layers are silicon layers and the intermediate layer is an inorganic material layer.   14. The method of manufacturing a liquid ejection head according to claim 12, wherein a lead wiring connected to the piezoelectric element and an electrode pad connected to the lead wiring are provided in the second recess. Providing an electrode pad in the vicinity of the interface between the first layer and the diaphragm plate;
The lead wire extending through the second concave portion, penetrating the first layer, extending through the boundary surface, and connecting the piezoelectric element to the electrode pad is provided. Manufacturing method of the liquid discharge head. Providing a CMOS switch inside the aperture plate;
14. A lead wire extending through the second recess, penetrating through the first layer, extending through the inside of the aperture plate, and connecting the piezoelectric element to the CMOS switch is provided. A manufacturing method of a liquid discharge head given in 2.   14. The liquid ejection head according to claim 12, wherein a plurality of the piezoelectric elements and a plurality of lead wirings connected to each piezoelectric element and led out in the same direction are provided in one second recess. Production method.   14. The liquid according to claim 12, wherein each of the plurality of second recesses is provided with the piezoelectric element and a lead wiring connected to the piezoelectric element and drawn in the same direction as other lead wiring. Manufacturing method of the discharge head.   19. The method of manufacturing a liquid ejection head according to claim 18, wherein each lead-out wiring extends in the corresponding second concave portion and extends on the surface of the second layer outside the second concave portion.   The method for manufacturing a liquid ejection head according to claim 12, wherein a lid member that covers the second recess is provided.   21. The method of manufacturing a liquid ejection head according to claim 20, wherein at least one of a lead wiring connected to the piezoelectric element and an electrode pad connected to the lead wiring is formed on the lid member.   The method of manufacturing a liquid ejection head according to any one of claims 12 to 21, wherein a protective film is provided to cover a piezoelectric body of the piezoelectric element and a pair of electrodes sandwiching the piezoelectric body. A first layer, a second layer, an intermediate layer disposed between the first layer and the second layer and in physical contact with the first layer and the second layer; The first layer includes a first recess that partially exposes the intermediate layer and forms a pressure chamber that stores liquid, and the second layer discharges liquid. An outlet and a second recess that partially exposes the intermediate layer, the intermediate layer having a through hole that communicates the discharge port with the pressure chamber;
A diaphragm plate having a diaphragm opening that covers the first recess of the first silicon layer and allows liquid to flow into the pressure chamber;
And a piezoelectric element provided in the exposed intermediate layer of the second recess.

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