JP2007069445A - Liquid ejection head, its manufacturing process and liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection head in which stripping of a bonding wire is prevented and a drive IC and the bonding wire are sealed surely. <P>SOLUTION: The liquid ejection head comprises a drive IC 120 for driving a pressure generation element, a bonding wire 130 for connecting a wire led out from the pressure generation element electrically with the drive IC 120, and a head case provided by an IC holding section 151, i. e. a space surrounding the drive IC 120, penetrating in the thickness direction wherein the drive IC 120 and the bonding wire 130 are covered with a potting agent layer 250 provided in the IC holding section 151. The potting agent layer 250 has a two-pack type potting agent layer 251 composed of a two-pack type potting agent covering at least the joint of the bonding wire 130 and the lead wire, and a one-pack type potting agent layer 252 composed of a one-pack type potting agent applied onto the two-pack type potting agent layer 251. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head, a manufacturing method thereof, and a liquid ejecting apparatus, and in particular, ejects ink droplets by displacement of a pressure generating element provided corresponding to a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets. The present invention relates to an ink jet recording head, a manufacturing method thereof, and an ink jet recording apparatus.

  Some liquid ejecting heads are provided with pressure generating elements such as piezoelectric elements and heat generating elements corresponding to pressure generating chambers communicating with nozzle openings for discharging ink droplets. As a liquid ejecting head using a piezoelectric element as a pressure generating element, for example, a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets is configured by a diaphragm, and the diaphragm is deformed by the piezoelectric element. There is an ink jet recording head that pressurizes ink in a pressure generating chamber and ejects ink droplets from nozzle openings. Two types of ink jet recording heads have been put into practical use, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element and one using a flexural vibration mode piezoelectric actuator. . As an example of using an actuator in a flexural vibration mode, for example, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique, and this piezoelectric material layer is formed into a pressure generating chamber by a lithography method. A device in which a piezoelectric element is formed so as to be cut into a corresponding shape and independent for each pressure generating chamber is known.

  Further, such an ink jet recording head requires a drive IC (semiconductor integrated circuit) for driving the piezoelectric element. This drive IC is mounted on a bonding substrate to be bonded to the flow path forming substrate in which the pressure generating chamber is formed, for example, a fixing member that structurally holds and fixes the head chip, and is electrically connected to each piezoelectric element by wire bonding. A structure to connect to is adopted. And this drive IC and the bonding wire are protected by covering with a mold (refer patent document 1).

  A resin material or the like is generally used as a mold material for covering such a driving IC or the like. Here, when a potting agent made of a one-component resin is used as the mold material, when the ink jet recording head is heated, the second of the bonding wires provided in the region away from the surface of the potting agent in the depth direction There is a problem that peeling may occur in the bonding portion.

  On the other hand, as a mold material that covers the drive IC, etc., a potting agent made of a two-component reactive urethane resin is used to fill the head case provided on the bonded substrate and cover the drive IC (patent) Reference 2). However, when a two-component potting agent is used, curing proceeds when the main agent and the curing agent are mixed, so the viscosity change of the two-component potting agent is significant, and it is difficult to manage the amount of potting agent. In addition, the bonding wires cannot be sufficiently sealed, resulting in poor insulation or a phenomenon that the potting agent rides on the head case. Such a problem exists not only in an ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject liquid other than ink.

JP 2000-135790 A (Figs. 5-8, 11, 12, 14) JP 2004-168038 A (paragraph number [0042] etc.)

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting head, a manufacturing method thereof, and a liquid ejecting apparatus in which a bonding IC is prevented from peeling and a driving IC and a bonding wire are securely sealed. .

According to a first aspect of the present invention for solving the above-described problem, a pressure generating element provided corresponding to a pressure generating chamber communicating with a nozzle opening for ejecting liquid, and a driving IC for driving the pressure generating element, A head case provided with a bonding wire for electrically connecting the lead-out wiring led out from the pressure generating element and the drive IC, and an IC holding portion which is a space surrounding the drive IC penetrating in the thickness direction The driving IC and the bonding wire are covered with a potting agent layer provided in the IC holding portion, and the potting agent layer covers at least a connection portion between the bonding wire and the lead-out wiring 2. One-component type consisting of a two-component potting agent layer made of a liquid-type potting agent and a one-component potting agent laminated on the two-component potting agent layer A liquid-jet head characterized by having a potting agent layer.
In the first aspect, since the connection portion between the bonding wire and the lead-out wiring is covered with a two-component potting agent layer that has no uncured region and can be completely cured, peeling of the bonding wire at the connection portion is prevented. Therefore, a highly reliable liquid jet head can be obtained. Further, since the surface side of the potting agent layer is a one-pack type potting agent, the driving IC and the bonding wire can be reliably sealed by the potting agent layer, and the potting agent rides on the head case or the like, or the bonding wire or the like is exposed. Does not occur.

According to a second aspect of the present invention, in the first aspect, the head case is bonded onto a protective substrate bonded to one surface of the flow path forming substrate in which the pressure generation chamber is formed, and the lead wiring and the A connection portion with a bonding wire is provided in a through hole that penetrates the protective substrate in the thickness direction and communicates with the IC holding portion, and the two-component potting agent layer is provided in the through hole. The liquid ejecting head is characterized by the above.
In the second aspect, even if the bonding wire and the lead-out wiring are connected in a through hole that is a region away from the surface of the potting agent layer in the depth direction, the two liquids that are completely cured Since it is covered with the mold potting agent layer, it is possible to prevent the bonding wire from peeling off at the connection portion.

According to a third aspect of the present invention, in the first or second aspect, the bonding wire has one end connected to the drive IC and the other end connected to the lead-out wiring. Located in the liquid jet head.
In this third aspect, even if the connection strength of the connection portion between the bonding wire and the lead-out wiring is weak, the bonding wire is reliably prevented from being peeled off because it is covered with a completely cured two-component potting agent. can do.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the one-component potting agent and the two-component potting agent are silicone resins.
In the fourth aspect, the drive IC and the bonding wire are reliably sealed by using the silicone resin.

A fifth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to fourth aspects.
In the fifth aspect, the liquid ejecting apparatus including the highly reliable liquid ejecting head in which the driving IC and the lead-out wiring are securely connected by the bonding wire and the driving IC and the bonding wire are securely sealed by the potting agent layer. Can be realized.

According to a sixth aspect of the present invention, there is provided a lead-out wiring led out from a pressure generating element provided corresponding to a pressure generating chamber communicating with a nozzle opening for ejecting liquid, and a head case penetrating in the thickness direction. A driving IC for driving the pressure generating element placed in the IC holding unit is electrically connected by a bonding wire, and a connecting portion between at least the bonding wire and the lead-out wiring with a two-component potting agent The two-component potting agent is filled with a one-component potting agent, and the driving IC and the bonding wire are covered with a potting agent composed of the one-component potting agent and the two-component potting agent. The present invention is directed to a method for manufacturing a liquid jet head.
In the sixth aspect, the connection portion between the bonding wire and the lead-out wiring is covered with a two-component potting agent, so that the vicinity of the connection portion can be completely cured without an uncured region, and the bonding wire peels off at the connection portion. This prevents the liquid jet head from being highly reliable. Further, since the surface is a one-component potting agent, the driving IC and the bonding wire can be reliably sealed without causing inconveniences such as the potting agent riding on the head case or the like or exposing the bonding wire. .

According to a seventh aspect of the present invention, in the sixth aspect, after one end of the bonding wire is connected to the driving IC, the other end of the bonding wire is connected to the lead-out wiring. It is in the manufacturing method.
In the seventh aspect, it is possible to reliably prevent the bonding wire from being peeled off at the connection portion having low connection strength.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of FIG. As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 of 5 to 2 μm is formed. The flow path forming substrate 10 is provided with two rows in which a plurality of pressure generating chambers 12 are arranged in the width direction. In addition, a communication portion 13 is formed for each row of the pressure generation chambers 12 in a region outside the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10. It is communicated through. The communication part 13 constitutes a part of a reservoir that communicates with a reservoir part of a protective substrate, which will be described later, and serves as a common ink chamber for the pressure generating chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

Further, on the opening surface side of the flow path forming substrate 10, a protective film 51 used as a mask when forming the pressure generating chambers 12 is provided on the side opposite to the ink supply path 14 of each pressure generating chamber 12. A nozzle plate 20 having a nozzle opening 21 communicating in the vicinity of the end is fixed through an adhesive, a heat welding 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, and a glass ceramic or silicon single crystal of, for example, 2.5 to 20 [× 10 ⁻⁶ / ° C.]. It consists of a substrate or stainless steel.

  On the other hand, as described above, the elastic film 50 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. For example, an insulator film 55 having a thickness of about 0.4 μm is formed. Further, on the insulator film 55, a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0 A 0.05 μm upper electrode film 80 is laminated to form a piezoelectric element 300 as a pressure generating element provided corresponding to the pressure generating chamber 12 communicating with the nozzle opening 21 for ejecting ink. 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 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 the present embodiment, the elastic film 50, the insulator film 55, and the lower electrode film 60 constitute a diaphragm.

  A lead electrode 90 is connected to the vicinity of one end of the upper electrode film 80 of each piezoelectric element 300. The lead electrode 90 extends to the vicinity of the central portion of the flow path forming substrate 10 and is electrically connected by a bonding wire 130 to a driving IC 120 mounted on a protective substrate 30 described later.

  Further, on the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, there is a piezoelectric element holding portion 31 capable of ensuring a space that does not hinder its movement in a region facing the piezoelectric element 300, A protective substrate 30 having a thickness of 400 μm, for example, is bonded via an adhesive 35. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. The piezoelectric element holding portion 31 may be sealed, but may not be sealed. Further, in the present embodiment, the piezoelectric element holding portion 31 is provided for each row of the piezoelectric elements 300 arranged in parallel.

  In addition, a reservoir portion 32 constituting at least a part of the reservoir 110 is provided outside the piezoelectric element holding portions 31 of the protective substrate 30. These reservoir portions 32 are provided across the width direction of the pressure generating chamber 12 through the protective substrate 30 in the thickness direction, and are communicated with the communicating portion 13 of the flow path forming substrate 10 to each pressure generating chamber. Each of the reservoirs 110 is a common ink chamber for each of the 12 columns. In the present embodiment, in the region between the piezoelectric element holding portions 31 of the protective substrate 30, through holes 33 that penetrate the protective substrate 30 in the thickness direction are provided corresponding to the rows of the piezoelectric elements 300. ing. The lead electrode 90 drawn from each piezoelectric element 300 is exposed in the through hole 33 in the vicinity of its end. In addition, as such a 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 flow path forming substrate 10 and It was formed using a silicon single crystal substrate of the same material.

  A driving IC (semiconductor integrated circuit) 120 for driving the piezoelectric element 300 is provided on the surface of the protective substrate 30, that is, the surface opposite to the bonding surface with the flow path forming substrate 10. Implemented for each column. Each drive IC 120 and the lead electrode 90 that is a lead-out wiring led out from each piezoelectric element 300 are electrically connected by a bonding wire 130 in the through hole 33 of the protective substrate 30. In this embodiment, the lead electrode and the bonding wire 130 are connected in the through hole 33. However, a connection portion between the lead electrode and the bonding wire may exist on the protective substrate. In this embodiment, the bonding wire 130 is one in which one end is connected to the driving IC 120 by wire bonding and the other end is connected to the lead electrode 90. In wire bonding, the second bonding side of the bonding wire 130, that is, the connection portion between the bonding wire 130 and the lead electrode 90 has a relatively higher connection strength than the first bonding side, that is, the connection portion between the bonding wire 130 and the driving IC 120. It becomes weak.

  Further, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded on the protective substrate 30 so as to surround a peripheral portion including a region corresponding to the reservoir portion 32. 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). The sealing film 41 seals one surface of the reservoir portion 32. 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 110 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 110 is sealed only by the flexible sealing film 41. Has been.

  In the present embodiment, the head case 200 having an IC holding portion 151 that is a space surrounding the drive IC 120 on the protective substrate 30 and having a thickness of, for example, 2 to 3 mm is bonded via an adhesive (not shown). Yes. In the present embodiment, the head case 200 is bonded to a compliance substrate 40 provided on the protective substrate 30. The head case 200 is formed, for example, by injection molding a thermosetting resin or a thermoplastic resin, and the IC holding portion 151 is provided so as to penetrate the head case 200 in the thickness direction. The head case 200 has one end connected to an ink cartridge (not shown) and the other end formed with an ink communication hole 202 connected to the reservoir 110. The ink communication hole 202 is connected to the reservoir 110 through the ink communication hole 202. Is to be supplied.

  Further, a potting agent layer 250 is provided in the IC holding portion 151 of the head case 200 so as to cover the driving IC 120 and the bonding wire 130. The potting agent layer 250 was laminated on the two-component potting agent layer 251 made of a two-component potting agent that covers at least the connection portion between the bonding wire 130 and the lead electrode 90, and the two-component potting agent layer 251. It consists of a one-component potting agent layer 252 made of a one-component potting agent. In this embodiment, the two-component potting agent layer 251 is provided so as to fill the entire region in the through hole 33 of the protective substrate 30 to which the bonding wire 130 and the lead electrode 90 are connected. Further, the one-pack type potting agent layer 252 is provided so that the driving IC 120 and the bonding wire 130 are not exposed from the surface.

  Here, the curing of the one-part type potting agent proceeds by reacting with moisture in the air. Therefore, since the curing proceeds in the depth direction from the surface in contact with air, when the driving IC 120 and the bonding wire 130 are covered only with the one-pack type potting agent, the surface is separated from the surface of the potting agent layer 250 in the depth direction. In a region where the potting agent is present, for example, at the bottom of the through-hole 33, the potting agent is difficult to cure and an uncured region is likely to occur. For this reason, in the vicinity of the connection portion between the bonding wire 130 and the lead electrode 90 provided at the bottom of the through-hole 33, there is a region where the potting agent has been cured and an uncured region. Due to the difference in linear expansion coefficient, a stress difference is locally generated and the bonding wire is lifted (peeled). In addition, it is thought that by increasing the time for curing the potting agent, it is possible to completely cure the region away from the surface in the depth direction even if only one-component potting agent is used. This is not preferable because the properties are lowered. On the other hand, a two-component potting agent is composed of a main agent and a curing agent, and curing proceeds by mixing the main agent and the curing agent. However, since the two-component potting agent cures immediately after mixing the main agent and the curing agent, the viscosity becomes high and the viscosity change is remarkably difficult to manage the amount of the potting agent. For this reason, when the amount of the potting agent is insufficient, the bonding wires 130 and the like are exposed, and the insulation coating is insufficient, resulting in poor insulation, causing an electrical failure and possibly causing the head function to stop. In addition, when the amount of potting agent is excessive, a phenomenon that the potting agent rides on the head case 200 or the like occurs, and when other members are joined to the head case 200 or the like, a bonding failure may occur, and an air leak failure may occur. .

  However, in the present invention, since the connecting portion between the bonding wire 130 and the lead electrode 90 is covered with the two-component potting agent layer 251 made of the two-component potting agent, curing proceeds from the inside rather than the surface. Thus, the bonding wire 130 can be prevented from peeling off. In particular, in the present embodiment, the lead electrode 90 that is the lead-out wiring and the bonding wire 130 are connected at the bottom of the through-hole 33 provided in the protective substrate 30 and are separated from the surface of the potting agent layer 250 in the depth direction. However, since the connection portion is covered with the two-component potting agent layer 251, peeling can be reliably prevented. Further, since the one-component potting agent layer 252 covering the two-component potting agent layer 251 does not proceed with curing unless it comes into contact with moisture in the air, the change in viscosity is extremely small, so that the amount is easy to manage quantitatively. The drive IC 120 and the bonding wire 130 can be reliably covered without being deficient or excessive, and problems such as riding on other members are unlikely to occur.

  Therefore, the lead IC 90 and the bonding wire 130 are peeled off by covering the driving IC 120 and the bonding wire 130 with the potting agent layer 250 including the two-component potting agent layer 251 and the one-component potting agent layer 252. The drive IC 120 and the bonding wire 130 can be reliably sealed without fail and without causing an insulation failure or the like.

  In addition, the kind of 1 liquid type potting agent and 2 liquid type potting agent is not specifically limited, For example, a silicone resin, a urethane resin, etc. are mentioned. In this embodiment, a silicone resin is used as the main component of the one-component potting agent and the two-component potting agent.

  In the present embodiment, the entire region in the through-hole 33 is filled with the two-component potting agent layer 251. However, the two-component potting agent layer 251 has at least a connection portion between the bonding wire 130 and the lead electrode 90. For example, it may be provided only in the vicinity of the connection portion between the bonding wire 130 and the lead electrode 90. Further, the two-component potting agent layer 251 may be provided up to the upper side of the through-hole 33. For example, the connection portion between the driving IC 120 and the bonding wire 130 may be covered with the two-component potting agent layer 251. Thereby, peeling of the connecting portion between the driving IC 120 on the first bonding side and the bonding wire 130 can be reliably prevented.

  Furthermore, in this embodiment, the example in which the driving IC 120 and the lead electrode 90 are electrically connected by the bonding wire 130 has been shown. However, the potting agent described above is applied to all the wirings connected to the bonding wire of the liquid jet head. Structure can be applied. Other than the lead electrode 90, for example, although not shown, a bonding wire for connecting the lower electrode film 60 and the drive IC 120, a terminal portion of a wiring electrode formed on the surface of the protective substrate 30 on which the drive IC 120 is provided, and the drive IC 120. Examples thereof include a bonding wire for connecting the terminal portion.

  In such an ink jet recording head, ink is taken in from an external ink supply unit such as an ink cartridge through an ink communication hole 202 provided in the head case 200. Then, after filling the interior from the reservoir 110 to the nozzle opening 21 with ink, it is driven between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12 in accordance with a drive signal from the drive IC 120. A voltage is applied, and the pressure in each pressure generating chamber 12 is increased by the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70, and ink droplets are ejected from the nozzle openings 21.

  Here, a method of manufacturing such an ink jet recording head will be described with reference to FIGS. 3 to 6 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction. FIG. 7 is an enlarged view showing an example of a wire bonding method. First, the flow path forming substrate 10 made of a silicon single crystal substrate is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film 52 to be an elastic film 50 and a protective film 51 is formed on the surface.

Next, as shown in FIG. 3A, an insulator film 55 made of zirconium oxide is formed on the elastic film 50 (silicon dioxide film 52). Specifically, after forming a zirconium (Zr) layer on the elastic film 50 (silicon dioxide film 52) 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. Next, as shown in FIG. 3B, for example, platinum and iridium are laminated on the insulator film 55 to form the lower electrode film 60, and then the lower electrode film 60 is patterned into a predetermined shape. Thereafter, for example, the piezoelectric layer 70 made of lead zirconate titanate (PZT) is formed by using, for example, a sol-gel method. The material of the piezoelectric layer 70 is not limited to lead zirconate titanate, and other piezoelectric materials such as relaxor ferroelectrics (for example, PMN-PT, PZN-PT, PNN-PT, etc.) are used. May be. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or the like may be used.

  Next, for example, the upper electrode film 80 made of iridium is formed on the entire surface of the flow path forming substrate 10. Next, as shown in FIG. 3C, the piezoelectric layer 300 and the upper electrode film 80 are patterned in a region facing each pressure generating chamber 12 to form the piezoelectric element 300. Next, as shown in FIG. 3D, after the lead electrode 90 made of, for example, gold (Au) is formed over the entire surface of the flow path forming substrate 10, for example, a mask pattern made of, for example, a resist (illustrated). Pattern) for each piezoelectric element 300.

  Next, as shown in FIG. 4A, a protective substrate 30 having a piezoelectric element holding portion 31 and a reservoir portion 32 formed of a silicon single crystal substrate in advance on the piezoelectric element 300 side of the flow path forming substrate 10 is provided. Bonded on the flow path forming substrate 10 via an adhesive 35. Next, the protective film 51 is formed by patterning the silicon dioxide film 52 opposite to the surface on which the piezoelectric element 300 of the flow path forming substrate 10 is formed into a predetermined shape, and the flow path is formed using the protective film 51 as a mask. By performing anisotropic etching (wet etching) on the substrate 10 using an alkaline solution such as KOH, the pressure generating chamber 12, the communication portion 13, the ink supply path 14, and the like are formed on the flow path forming substrate 10.

  After that, as shown in FIG. 4B, the nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate 10 opposite to the protective substrate 30 is joined and the protective substrate 30 is compliant. The substrate 40 is bonded.

  Next, as shown in FIG. 5A, the drive IC 120 is mounted on the protective substrate 30. Specifically, the driving IC 120 is bonded onto the protective substrate 30, and the driving IC 120 and the lead electrode 90 are connected by the bonding wire 130 by wire bonding. Here, an example of a wire bonding method will be described with reference to FIG. As shown in FIG. 7A, the bonding wire 130 is held in a state of being inserted through a capillary 135 that constitutes a wire bonding apparatus, and is connected to a terminal portion of the driving IC 120 by ball bonding. As a connection method by this ball bonding, a sphere is formed by melting the tip of the bonding wire 130, and this sphere is pressed against the terminal portion of the drive IC 120. Next, as shown in FIG. 7B, the bonding wire 130 is connected to the terminal portion of the lead electrode 90 by applying a load and pressing.

  Next, as shown in FIG. 5B, the head case 200 provided with the IC holding part 151 is joined to the compliance substrate 40 fixed on the protective substrate 30. For example, in this embodiment, the head case 200 is bonded to the compliance substrate 40 with an adhesive.

  Next, from the opening opposite to the protective substrate 30 of the IC holding unit 151, for example, a two-component potting agent mainly composed of silicone resin and a one-component potting agent are sequentially filled by a nozzle needle (not shown). The agent layer 250 is formed. Specifically, first, as shown in FIG. 6A, the two-hole potting agent in which the main agent and the curing agent are mixed in advance is filled in the through-hole 33, and the bonding wire 130, the lead electrode 90, Cover the connection. Next, as shown in FIG. 6B, the one-part potting agent is filled in the IC holding part 151. Thus, the one-component potting agent is laminated on the two-component potting agent so that the driving IC 120 and the bonding wire 130 are not exposed from the surface of the one-component potting agent. Since the one-component potting agent does not proceed unless it comes into contact with moisture in the air and the viscosity change is extremely small, the IC holding part 151 can be easily filled with a predetermined amount. Insulation failure due to exposure and joining failure of other members due to the phenomenon that the potting agent rides on the head case 200 or the like does not occur.

  Thereafter, for example, the two-part potting agent layer 251 and the one-part potting agent layer 252 are cured by being left to stand at 25 ° C. and a humidity of 55% for 24 hours to cure the one-part type potting agent and the two-part type potting agent. A potting agent layer 250 is formed. Thereby, since the connection part of the bonding wire 130 and the lead electrode 90 is covered with the completely cured two-component potting agent layer 251, peeling of the bonding wire 130 can be prevented.

  By manufacturing the liquid ejecting head in this manner, the lead electrode 90 and the bonding wire 130 are surely prevented from being peeled off, and the drive IC 120 and the bonding wire 130 are securely sealed without causing an insulation failure or the like. Can be stopped.

  In this embodiment, after the protective substrate 30 is bonded to the flow path forming substrate 10, the drive IC 120 is bonded to the protective substrate 30, and then the head case 200 is bonded to the protective substrate 30. The order of assembling the formation substrate 10, the drive IC 120, the head case 200, and the like is not particularly limited. For example, after the drive IC 120 is provided on the protection substrate 30, the protection substrate 30 and the flow path formation substrate 10 may be joined. .

  In practice, a large number of chips are simultaneously formed on a single wafer by the above-described series of film formation and anisotropic etching, and after the completion of the process, a single chip size channel is formed as shown in FIG. An ink jet recording head is formed by dividing each substrate 10.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above.

  For example, in the above-described embodiment, a thin film type liquid jet head manufactured by applying a film forming and lithography process is taken as an example. However, the present invention is not limited to this, and for example, a green sheet is attached. The present invention can also be applied to a thick film type liquid jet head formed by this method.

  In the above-described embodiment, the flexural vibration type ink jet recording head is exemplified, but the present invention is not limited to this. For example, a longitudinal vibration type in which piezoelectric materials and electrode forming materials are alternately stacked to expand and contract in the axial direction. The present invention can be applied to ink jet recording heads having various structures, such as the ink jet recording head.

  In addition, although the piezoelectric element has been described as the pressure generating element provided corresponding to the pressure generating chamber communicating with the nozzle opening for ejecting ink droplets, the pressure generating element is not limited to the piezoelectric element, and is drawn from other elements such as a heating element. The present invention can also be applied to a connection portion between a bonding wire connected to the lead-out wiring and the lead-out wiring.

  Further, the ink jet recording head of the above-described embodiment constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on the ink jet recording apparatus. FIG. 8 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 8, the recording head units 1A and 1B having the head main body are detachably provided with cartridges 2A and 2B constituting the ink supply means, and the carriage 3 on which the recording head units 1A and 1B are mounted is A carriage shaft 5 attached to the apparatus body 4 is provided so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively. The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  In the above-described embodiment, the ink jet recording head has been described as an example of the liquid ejecting head of the present invention. However, the basic configuration of the liquid ejecting head is not limited to the above-described configuration. Of course, the present invention can also be applied to a liquid ejecting liquid other than ink. 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 FED (surface emitting). Examples thereof include an electrode material ejection head used for electrode formation such as a display, and a bioorganic matter ejection head used for biochip production.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. 6 is a cross-sectional view illustrating a manufacturing process of the liquid jet head according to Embodiment 1. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the liquid jet head according to Embodiment 1. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the liquid jet head according to Embodiment 1. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the liquid jet head according to Embodiment 1. FIG. FIG. 6 is an enlarged view illustrating a manufacturing process of the liquid jet head according to the first embodiment. 1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Piezoelectric element holding | maintenance part, 32 Reservoir part, 33 Through-hole, 40 Compliance board, 50 elastic film, 55 insulator film, 60 lower electrode film, 70 piezoelectric layer, 80 upper electrode film, 90 lead electrode, 110 reservoir, 120 driving IC, 130 bonding wire, 151 IC holding part, 200 head case, 250 potting Agent layer, 251 two-component potting agent layer, 252 one-component potting agent layer, 300 piezoelectric element

Claims (7)

A pressure generating element provided corresponding to a pressure generating chamber communicating with a nozzle opening for ejecting a liquid; a driving IC for driving the pressure generating element; a lead-out line led out from the pressure generating element; and the driving A bonding wire that electrically connects the IC, and a head case provided with an IC holding portion that is a space surrounding the driving IC penetrating in the thickness direction;
The driving IC and the bonding wire are covered with a potting agent layer provided in the IC holding portion, and the potting agent layer is formed from a two-component potting agent that covers at least a connection portion between the bonding wire and the lead-out wiring. A liquid ejecting head comprising: a two-component potting agent layer, and a one-component potting agent layer made of a one-component potting agent laminated on the two-component potting agent layer. 2. The head case is bonded to a protective substrate bonded to one surface of a flow path forming substrate in which the pressure generating chamber is formed, and a connection portion between the lead-out wiring and the bonding wire is connected to the protection wire. A liquid ejecting head, wherein the liquid ejecting head is provided in a through hole that is provided through the substrate in a thickness direction and communicates with the IC holding portion, and the two-liquid potting agent layer is provided in the through hole. . 3. The liquid ejecting head according to claim 1, wherein the bonding wire has one end connected to the drive IC and the other end connected to the lead-out wiring. The liquid ejecting head according to claim 1, wherein the one-liquid type potting agent and the two-liquid type potting agent are silicone resins. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1. Placed in a lead wire drawn out from a pressure generating element provided corresponding to a pressure generating chamber communicating with a nozzle opening for ejecting liquid, and in an IC holding portion provided in the head case penetrating in the thickness direction Further, the two-liquid type is formed by electrically connecting a driving IC for driving the pressure generating element by a bonding wire and covering at least a connection portion between the bonding wire and the lead-out wiring with a two-liquid potting agent. A liquid ejecting head comprising: a potting agent filled with a one-component potting agent; and the driving IC and the bonding wire are covered with a potting agent comprising a one-component potting agent and a two-component potting agent. Production method. 7. The method of manufacturing a liquid jet head according to claim 6, wherein after one end of the bonding wire is connected to the driving IC, the other end of the bonding wire is connected to the lead-out wiring.

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