JP2007090521A - Diaphragm, diaphragm assembly, liquid drop ejection head, and liquid drop ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm producing sufficient deformation even in case of small area and ensuring a high discharge volume efficiency even when it is used in a small pressure chamber, and to provide a diaphragm assembly including the diaphragm, a liquid drop ejection head equipped with the diaphragm, and a liquid drop ejector equipped with the liquid drop ejection head. <P>SOLUTION: The diaphragm used in such a liquid drop ejection head as the wall face of a pressure chamber communicating with a nozzle is formed at least partially of the diaphragm and ejecting a liquid drop from the nozzle by vibrating the diaphragm consists of a metal layer and a resin layer wherein the resin layer is thicker than the metal layer. A diaphragm assembly having the diaphragm, a liquid drop ejection head, and a liquid drop ejector are also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vibration plate, a vibration plate assembly, a droplet discharge head, and a droplet discharge device, and in particular, a vibration plate capable of obtaining a large amount of deformation even when a pressure chamber is small in the droplet discharge head, and the vibration The present invention relates to a diaphragm assembly including a plate, a droplet discharge head provided with the diaphragm, and a droplet discharge device including the droplet discharge head.

  As an ink jet recording head, for example, an ink supply unit is arranged on the vibration plate side of the actuator unit, and the vibration plate of the actuator unit is placed on the cavity forming substrate on which a plurality of pressure generation chambers are formed. An ink supply port that extends outward and penetrates the region outside the plurality of pressure generation chambers of the diaphragm corresponding to each pressure generation chamber and communicates with each pressure generation chamber is formed. A communication with the ink supply unit has been proposed (Patent Document 1).

The diaphragm is a laminate of a resin film and a SUS material, and the thickness T of the resin film is shorter than the width W of the liquid chamber in the short direction.
Approximately 0.035W <T <0.065W
The width W2 of the contact surface between the piezoelectric element and the diaphragm is within the range W in the short direction of the liquid chamber.
About 0.035W <W2 <0.045W
Ink jet recording heads in the range of (2) have also been proposed (Patent Document 2). In the patent document, as an example of the diaphragm, a SUS material having a thickness of 30 μm and a polyimide resin film having a thickness of 4 μm is exemplified.
JP 2001-179773 A JP 2000-334946 A

  In the past, SUS (stainless steel) material has been widely used as a vibration plate for ink jet recording heads. However, in recent years, in order to improve printing image quality, it is desired to increase printing density to improve printing image quality. With the increasing demand, the pressure chamber has been miniaturized to increase the density of the print head.

  However, if the pressure chamber is reduced in size, the area of the diaphragm is also reduced. Therefore, when a material having a large Young's modulus such as SUS material is used for the diaphragm, a sufficient amount of deformation cannot be obtained. There is a problem that decreases.

  The present invention has been made in order to solve the above-mentioned problem. A diaphragm capable of obtaining a sufficient amount of deformation even when the area is small and achieving high discharge volume efficiency even when used in a small pressure chamber, It is an object of the present invention to provide a diaphragm assembly including a diaphragm, a droplet discharge head provided with the diaphragm, and a droplet discharge apparatus including the droplet discharge head.

  The invention according to claim 1 is used in a droplet discharge head in which at least a part of a wall surface of a pressure chamber communicating with a nozzle is formed by a vibration plate, and the vibration plate is vibrated to discharge a droplet from the nozzle. The diaphragm includes a metal layer and a resin layer, and the thickness of the resin layer is greater than the thickness of the metal layer.

  Since the diaphragm can obtain a large amount of deformation even when the area is small, droplets can be ejected with high discharge efficiency even when used in a high-density droplet ejection head having a small pressure chamber.

  In addition, pinholes are likely to occur when the metal layer is thin, but pinholes are unlikely to occur in the resin layer, so pinholes are unlikely to occur in the entire diaphragm.

  The invention according to claim 2 relates to the diaphragm according to claim 1, wherein the metal layer is a copper layer and the resin layer is a polyimide resin layer.

  Copper can be easily processed into foil and the like. On the other hand, if the polyimide is also soluble in a polar solvent such as p-chlorophenol or N-methylpyridone, a pinhole is formed by a casting method in which a dope obtained by dissolving polyimide in the polar solvent is cast on a metal belt or the like and dried. A film having no defects such as can be easily produced. Moreover, the obtained film can be easily bonded to the copper foil by heating to the glass transition point or higher.

  Further, since copper has high electrical conductivity, it can be used as a drive electrode for applying a drive voltage to the piezoelectric element.

  Furthermore, since polyimide resin has a high Young's modulus as a resin, the diaphragm has a high response frequency because of its high resonance frequency, although it can take a large amount of deformation. It is advantageous.

  The invention according to claim 3 relates to the diaphragm according to claim 2, wherein the copper layer and the polyimide resin layer are formed by heating and press-bonding a copper foil and a polyimide resin film.

  As described above, the diaphragm can be easily manufactured by simply heat-pressing a polyimide resin film and a copper foil, and the polyimide resin film and the copper foil can be bonded together without using an adhesive or the like.

  According to a fourth aspect of the present invention, there is provided the diaphragm according to any one of the first to third aspects, a piezoelectric element joined to a metal layer of the diaphragm, and driving for applying a driving voltage to the piezoelectric element. An electrode assembly, wherein one of the drive electrodes is bonded to one surface of the piezoelectric element and the other of the drive electrodes is bonded to the other surface of the piezoelectric element. Concerning solids.

  In the diaphragm assembly, a droplet discharge head can be manufactured by joining the opposite side of the diaphragm to the side where the piezoelectric elements are joined to a support body on which a pressure chamber and a nozzle are formed. Therefore, it is possible to omit the trouble of joining the piezoelectric element to the diaphragm and providing the driving electrode on the piezoelectric element.

The invention according to claim 5 relates to the diaphragm assembly according to claim 4, wherein one of the drive electrodes is formed by a metal layer in the diaphragm. In the diaphragm assembly, the metal in the diaphragm Since the layer is used as one of the drive electrodes, for example, as a common electrode, there is no need to provide a common electrode separately. Therefore, the assembly has a simple configuration.

  The invention according to claim 6 includes an electrode assembly formed by laminating a resin film and the other of the drive electrodes, and the other of the drive electrodes includes the diaphragm with the electrode assembly sandwiching the piezoelectric element. The diaphragm assembly according to claim 5, wherein the diaphragm assembly is electrically bonded to the piezoelectric element by being bonded to the piezoelectric element.

  In the diaphragm assembly, the other of the drive electrodes, for example, the individual electrode can be joined to the piezoelectric element by joining the electrode assembly to the surface of the diaphragm where the piezoelectric element is joined. Therefore, it is possible to omit the trouble of joining each individual electrode to the piezoelectric element.

  Moreover, since the electrode assembly is formed by laminating the resin film, the other of the drive electrodes, and the electrical wiring, the thickness can be reduced. Therefore, the entire diaphragm assembly can be made thin.

  The invention described in claim 7 is the nozzle according to any one of claims 1 to 3, which forms at least a part of a nozzle from which droplets are discharged, a pressure chamber communicating with the nozzle, and a wall surface of the pressure chamber. And a piezoelectric element that vibrates the diaphragm, wherein the piezoelectric element is bonded to a metal layer side of the diaphragm.

  Since the diaphragm used for the droplet discharge head can obtain a large amount of deformation even when the area is small, the droplet discharge head can discharge droplets with high discharge efficiency even when the pressure chamber is downsized. Can be discharged.

  In addition, since it is difficult for pinholes to occur in the entire diaphragm, there is no leakage of the discharge liquid derived from the pinholes.

  Invention of Claim 8 is joined to the support body in which the said nozzle and the pressure chamber were formed, and the surface of the side in which the pressure chamber in the said support body was formed in any one of Claims 4-6. 8. The liquid according to claim 7, wherein the diaphragm assembly is joined to the support on a surface of the diaphragm opposite to the side to which the piezoelectric element is joined. The present invention relates to a droplet discharge head.

  Since the droplet discharge head is formed by joining the diaphragm assembly to the surface of the support on the side where the pressure chamber is formed, the configuration can be simplified.

  A ninth aspect of the present invention relates to the droplet discharge head according to the eighth aspect of the present invention, wherein a region bonded to the piezoelectric element in the metal layer of the diaphragm is plated with gold.

  In the liquid droplet ejection head of the present invention, when a diaphragm having a copper layer is used as a metal layer, the surface of copper is easily oxidized by heating. Therefore, when the metal layer is used as a common electrode of a piezoelectric element, contact is made. Defects can occur.

  However, in the liquid droplet ejection head according to the above claims, since the region bonded to the piezoelectric element in the metal layer of the diaphragm is plated with gold, the surface of the metal layer is oxidized by heating, and the piezoelectric element It is possible to prevent poor contact between them.

  According to a tenth aspect of the present invention, the region of the metal layer of the diaphragm has a larger area than the pressure chamber, and is formed from the inside to the outside of the pressure chamber. The droplet discharge head described in 1.

  In the droplet discharge head, since the outer edge of the metal layer region of the vibration plate exists outside the pressure chamber, the deformation stress of the vibration plate is concentrated on the edge of the pressure chamber, and the vibration plate Is prevented from being damaged.

  According to an eleventh aspect of the present invention, there is provided the liquid droplet ejection head according to any one of the seventh to tenth aspects, a driving IC that drives a piezoelectric element included in the liquid droplet ejection head, and the liquid droplet ejection head. The present invention relates to a droplet discharge device comprising discharge liquid supply means for supplying a discharge liquid discharged from a nozzle having the pressure chamber to the pressure chamber.

  Since the diaphragm provided in the droplet discharge device can obtain a large amount of deformation even when the area is small, the droplet discharge and discharge device discharges droplets with high discharge efficiency even when the pressure chamber is downsized. it can. Accordingly, the droplet discharge / discharge apparatus can easily cope with the reduction in size and density of the droplet discharge head.

  According to a twelfth aspect of the present invention, in the droplet discharge head, the droplet discharge head is bonded to a support body on which the nozzle and the pressure chamber are formed, and a surface of the support body on which the pressure chamber is formed. The diaphragm assembly is bonded to the support on the surface of the diaphragm opposite to the side on which the piezoelectric element is bonded, and the drive IC is The droplet discharge device according to claim 11, wherein the droplet assembly device is mounted on a surface of the diaphragm assembly opposite to a side bonded to the support.

  As described above, since the diaphragm assembly according to claim 6 is thin, the droplet discharge device can also be thinned by forming the support thin. Further, if the electric wiring connecting the drive IC and the drive electrode is embedded in an electrode assembly, the drive IC is mounted on the surface of the diaphragm assembly opposite to the side to be joined to the support. Just by doing this, the drive IC and the drive electrode are electrically connected.

  Therefore, the wiring of the driving IC can be greatly simplified.

  According to a thirteenth aspect of the present invention, the droplet discharge head is provided over the entire width of the print width that is a width in which droplets are discharged and printed by the droplet discharge device. It relates to the droplet discharge device described in 1.

  In the droplet discharge device, since the discharge head is fixed in the width direction, a mechanism for moving the discharge head in the width direction is unnecessary.

  According to a fourteenth aspect of the present invention, the discharge liquid supply means includes a discharge liquid supply chamber provided adjacent to a side of the diaphragm assembly opposite to a side bonded to the support, and the diaphragm. The droplet discharge device according to claim 12, further comprising a discharge liquid supply passage that penetrates the assembly and communicates the discharge liquid supply chamber and the pressure chamber.

  When the droplet discharge head is reduced in size, it is necessary to increase the degree of integration of the drive IC mounted on the droplet discharge head, so that the heat generation of the drive IC increases.

  However, in the droplet discharge device, since the discharge liquid supply chamber is provided on the side opposite to the side bonded to the support in the diaphragm assembly, in other words, on the side where the drive IC is mounted, The heat generated in the IC is effectively removed by the discharge liquid.

  The invention described in claim 15 relates to the droplet discharge device according to any one of claims 11 to 14, wherein the discharge liquid is ink.

  The droplet discharge device is an example in which the droplet discharge device of the present invention is applied to ink jet recording.

  As described above, according to the present invention, a sufficient amount of deformation can be obtained even when the area is small, and a diaphragm that can achieve high discharge volume efficiency even when used in a small pressure chamber, and a vibration including the diaphragm. A plate assembly, a droplet discharge head provided with the diaphragm, and a droplet discharge device including the droplet discharge head are provided.

1. Embodiment 1
An ink jet recording head 100, which is an example of a droplet discharge head according to the present invention, will be described below.

  As shown in FIG. 1, an ink jet recording head 100 according to Embodiment 1 includes a diaphragm assembly 40 in which a piezoelectric element 6 and a diaphragm 4 are incorporated, and a flow path assembly in which a pressure chamber 8 and a nozzle 10 are formed. 20 is laminated.

  The vibration plate assembly 40 includes a vibration plate 4 in which a polyimide resin film 4A and a copper foil 4B are bonded together, a piezoelectric element 6 bonded to the surface of the copper foil 4B of the vibration plate 4 with an epoxy resin adhesive 14, and vibrations. The electrode assembly 42 is bonded to the copper foil 4B side of the plate 4 and covers the piezoelectric element 6.

  In the diaphragm 4, the polyimide resin film 4A is thicker than the copper foil 4B. For example, when the thickness of the copper foil 4B is 9 μm, the thickness of the polyimide resin film 4A is larger than 9 μm and not more than 30 μm, specifically, the thickness of the polyimide resin film 4A can be 11 μm, 13 μm, or 15 μm. . Moreover, when the thickness of the copper foil 4B is 11 μm, the thickness of the polyimide resin film 4A can be set to 13 μm or 25 μm. It is preferable to use a thermoplastic polyimide resin film as the polyimide resin film 4A because the polyimide resin film 4A can be bonded to the copper foil 4B by being heated to a glass transition point or higher and pressure-bonded to the copper foil 4B. The copper foil 4B is used as a common electrode to which a plurality of piezoelectric elements 6 are connected.

  The electrode assembly 42 has a configuration in which individual electrodes 42A individually connected to the piezoelectric elements 6 are formed on one surface of the polyimide resin film 42B. The individual electrode 42A is formed by bonding a copper foil to one surface of the polyimide resin film 42B and patterning it. The polyimide resin film 42 </ b> B is the same as the polyimide resin film 4 </ b> A constituting the diaphragm 4. The side of the polyimide resin film 42B where the individual electrodes 42A are formed is covered with a resist resin layer 42C except for the portion where the piezoelectric element 6 is located. The resist resin layer 42C can be formed of a photocurable resist resin.

  The electrode assembly 42 is bonded with the anisotropic conductive film 12 so that the resist resin layer 42C side faces the copper foil 4B side of the diaphragm 4. Further, the individual electrode 42 </ b> A in the electrode assembly 42 is also bonded to the surface of the piezoelectric element 6 opposite to the side bonded to the diaphragm 4 by the anisotropic conductive film 12.

  The drive IC (not shown) is mounted on the surface of the electrode assembly 42 opposite to the side on which the individual electrodes 42A are formed, in other words, on the outer surface of the diaphragm assembly 40.

  The flow path assembly 20 includes a communication passage 27 that connects the pressure chamber 8 and the nozzle 10, an ink temporary storage chamber 29 provided on the upstream side of the pressure chamber 8, and an ink in the pressure chamber 8 through the ink temporary storage chamber 29. An ink supply channel (not shown) for supplying the ink. The pressure chamber 8 and the temporary ink storage chamber 29 communicate with each other through a communication path 29A. An air damper 30 is provided adjacent to the nozzle plate 21 side of the temporary ink storage chamber 29. The air damper 30 communicates with the outside through an air communication path 31.

  The flow path assembly 20 includes a nozzle plate 21, a first storage chamber plate 22A, a damper plate 23, a second storage chamber plate 22B, a third storage chamber plate 22C, a fourth storage chamber plate 22D, a first communication hole plate 24A, The separation plate 25, the second communication hole plate 24B, and the pressure chamber plate 26 are stacked and joined. The nozzle plate 21 and the like are made of SUS material.

  The flow path assembly 20 is formed on the surface of the pressure chamber 8 on the side where the pressure chamber plate 26 is formed, in other words, on the polyimide resin film 4A side of the vibration plate 4 included in the vibration plate assembly 40 by the polyimide resin adhesive. It is glued.

  The diaphragm assembly 40 can be manufactured according to the following procedure.

  First, as shown in FIG. 2A, the surface of the copper foil 4B of the diaphragm 4 is roughened by appropriate means so that the surface roughness Ra is 0.1 or more.

  Next, as shown in FIGS. 2B and 2C, the piezoelectric element 6 is bonded to the surface of the copper foil 4B by the epoxy resin adhesive 14. At this time, the unevenness of the surface of the piezoelectric element is about Ra = 3 μm, and electrical bonding can be secured at the convex portion even through an epoxy adhesive.

  On the other hand, as shown in FIG. 3A, the polyimide resin film 42B and the copper foil 42A are bonded together, and as shown in FIG. 3B, the copper foil is patterned and then etched to form the individual electrodes 42A. Make it. Then, as shown in FIG. 3C, a liquid resist resin is applied from above the individual electrode 42A and patterned to form a resist resin layer 42C.

  As shown in FIG. 4A, the electrode assembly 42 manufactured in this way is formed with the anisotropic conductive film 12 so that the resist resin layer 42C faces the copper foil 4B side of the diaphragm 4. To the diaphragm 4. At this time, a portion of the polyimide resin film 42B and the individual electrode 42A that is exposed without being covered with the resist resin layer 42C is overlapped with the piezoelectric element 6 bonded on the vibration plate 4. As a result, the exposed portion of the individual electrode 42 </ b> A is bonded to the piezoelectric element 6 through the anisotropic conductive film 12 as shown in FIG. Here, the anisotropic conductive film 12 is an adhesive film that develops conductivity in the thickness direction along with adhesiveness by applying a predetermined pressing force. Therefore, the individual electrode 42 </ b> A is electrically connected to the piezoelectric element 6. It should be noted that the copper foil 42A and the piezoelectric element 6 in the electrode assembly 42 can be electrically connected not by adhesion by the anisotropic conductive film 12 but also by pressure contact of bump-formed electrodes or solder balls.

  In the diaphragm assembly 40, as shown in FIG. 5A, the surface of the copper foil 4B of the diaphragm 4 is roughened, and a predetermined pattern is formed by patterning and etching. Next, as shown in (B) and (C) of the figure, the piezoelectric element 6 may be bonded with an epoxy resin adhesive 14 to the copper foil 4B on which a predetermined pattern is formed.

  Next, as shown in FIGS. 6A and 6B, the diaphragm 4 and the electrode assembly 42 having the configuration shown in FIG. 3 are bonded together with the anisotropic conductive film 12.

  If the surfaces of the copper foil 4B and the individual electrode 42A are plated with gold and then bonded to the piezoelectric element 6 and bonded to the diaphragm 4 and the electrode assembly 42, the surfaces of the copper foil 4B and the individual electrode 42A are obtained. Since it can be prevented from being oxidized by heat, it is possible to prevent contact failure due to surface oxidation.

  In the inkjet recording head 100 according to the first embodiment, the diaphragm 4 is formed by bonding the polyimide resin film 4A and the copper foil 4B, and the polyimide resin film 4A is thicker than the copper foil 4B. Even when the chamber 8 is small, a large amount of deformation can be obtained, so that the ink ejection efficiency is high. Therefore, the pressure chambers 8 and the nozzles 10 can be arranged with high density in the flow path assembly 20, and high print image quality can be obtained. Further, since the polyimide resin form 4B has almost no pinholes, even when the copper foil 4B is thinned, no failure due to the pinholes occurs.

  Moreover, since the diaphragm assembly 40 is formed by bonding the electrode assembly 42 and the diaphragm 4, the thickness can be reduced as a whole. Further, since the piezoelectric element 6 is sealed between the diaphragm 4 and the polyimide resin film 42B of the electrode assembly 42, it is effectively protected from the external environment.

  Further, in the flow path assembly, since the ink temporary storage chamber 29 is provided between the ink supply flow path (not shown) and the pressure chamber 8, the amount of ink supplied from the ink supply flow path is reduced. Even if it fluctuates, the fluctuation is absorbed in the temporary ink storage chamber 29, and ink droplets are stably ejected from the nozzle 10.

  Hereinafter, features of the inkjet recording head 100 will be described using specific data.

  The resonance frequency and displacement amount of the diaphragm 4 when the aspect ratio of the pressure chamber 8 is 1.8 and the size is equivalent to 600 dpi, equivalent to 800 dpi, and equivalent to 1200 dpi are shown in FIGS.

  As apparent from FIGS. 12 to 14, the diaphragm 4 in which a polyimide film having a thickness of 13 μm is bonded to a copper foil having a thickness of 9 μm has a polyimide film having a thickness of 1 μm bonded to a stainless steel foil having a thickness of 9 μm or 20 μm. When the size of the pressure chamber 8 is reduced from 600 dpi equivalent to 1200 dpi equivalent compared to a combined diaphragm or a diaphragm in which a 9 μm or 20 μm thick copper foil is laminated with a 1 μm thick polyimide film The degree of increase in the resonance frequency and the degree of decrease in the amount of displacement were small. Here, since the responsiveness is improved as the resonance frequency is increased, it is advantageous for the ejection of fine droplets and the high frequency ejection, but it is considered that a frequency of 500 kHz or more is usually sufficient. Even in the diaphragm 4 in which a polyimide film with a thickness of 13 μm is bonded to a copper foil with a thickness of 9 μm, the resonance frequency of 500 kHz is secured even when the size of the pressure chamber 8 is as large as 600 dpi.

  Next, the thickness of the copper foil is 9 μm, and the thickness of the polyimide film to be bonded is changed from 1 μm to 25 μm, and the results of examining the change in the maximum displacement and the resonance frequency are shown in FIGS. 15 and 16.

  As is clear from FIGS. 15 and 16, the maximum displacement amount decreases as the thickness of the polyimide film to be bonded increases, but the decrease amount is small. As for the resonance frequency, a curve having a minimum value is drawn, but the change due to the increase in the thickness of the polyimide film is small.

  Finally, the vibration plate 4 of the present invention in which a polyimide film having a thickness of 13 μm is bonded to a copper foil having a thickness of 9 μm, and a vibration plate in which a polyimide film having a thickness of 1 μm or 6 μm is bonded to a stainless steel foil having a thickness of 20 μm, 17 shows a change in the maximum displacement when the position of the piezoelectric element 6 (piezo element) deviates from the normal position. In FIG. 17, the numbers on the vertical axis indicate that the piezoelectric element 6 is displaced from the predetermined position with respect to the maximum displacement amount of the diaphragm when the piezoelectric element 6 is in a normal position, that is, when the displacement amount of the piezoelectric element 6 is zero. The ratio of the maximum displacement amount of the diaphragm is shown.

  As is clear from FIG. 17, the vibration plate 4 in which a 13 μm thick polyimide film is bonded to a 9 μm thick copper foil has a maximum displacement of 0 when the displacement of the piezoelectric element 6 is 25 μm. It was 0.97 times that of. On the other hand, in a diaphragm in which a 1 μm thick polyimide film is bonded to a 20 μm thick stainless steel foil, the maximum displacement when the displacement of the piezoelectric element 6 is 25 μm is 0 when the displacement is 0. It was reduced to 91 times.

  Thus, it can be seen from the above-mentioned data that a large deformation amount can be obtained even when the pressure chamber 8 is small if the diaphragm 4 is used. Furthermore, it is clear from the above data that the use of the diaphragm 4 can alleviate the influence on the maximum displacement when the piezoelectric element is displaced from the normal position.

2. Embodiment 2
Another example of the ink jet recording head included in the droplet discharge head according to the present invention will be described below.

  As shown in FIG. 7, the ink jet recording head 200 according to the second embodiment includes a diaphragm assembly 40 in which the piezoelectric element 6 and the diaphragm 4 are incorporated, a pressure chamber plate 50 in which the pressure chamber 8 is formed, and a continuous structure. The flow path plate 52 in which the passage 27 is formed and the nozzle plate 54 in which the nozzle 10 is formed are stacked in the thickness direction. Further, an ink supply liquid chamber 60 that supplies ink to the plurality of ink jet recording heads 200 is provided on the opposite side of the pressure chamber 8 with the diaphragm assembly 40 interposed therebetween. Communicate. The ink supply liquid chamber 60 and the ink supply flow path 28 correspond to the discharge liquid supply chamber and the discharge liquid supply flow path in the present invention, respectively.

  Hereinafter, a procedure for manufacturing the diaphragm assembly 40 will be described.

  First, as shown to (A) in FIG. 8, the polyimide resin film 4A side of the diaphragm 4 is adhere | attached on the pressure chamber board 50 which is a SUS board material. The polyimide resin film 4A used in this embodiment is a self-bonding type and is bonded by thermocompression bonding.

  Next, as shown in FIG. 2B, the piezoelectric element 6 is bonded to the copper foil 4B side of the diaphragm 4 with an epoxy resin adhesive 14.

  When the piezoelectric element 6 is bonded, the pressure chamber plate 50 is etched to a depth reaching the vibration plate 4 to form the pressure chamber 8 as shown in FIG.

  When the pressure chamber 8 is formed, as shown in FIG. 9A, the electrode assembly 42 is bonded to the copper foil 4B side of the diaphragm 4 through the anisotropic conductive film 12, and the diaphragm assembly. 40 is produced. The configuration of the electrode assembly 42 and the procedure for bonding to the diaphragm 4 are as described in the first embodiment.

  When the electrode assembly 42 is bonded to the diaphragm 4, the ink supply channel 28 is drilled with a laser so as to penetrate the diaphragm assembly 40 as shown in FIG. 9B. At this time, it is preferable to previously remove the region for forming the ink supply flow path 28 in the copper foil 4B of the vibration plate 4 by patterning. As a result, the ink supply flow path 28 can be accurately formed by lowering the laser, there is no contact between the ink and the copper foil 4B, and the reliability can be increased.

  After the ink supply channel 28 is drilled in the diaphragm assembly 40, the channel plate 52 is bonded to the side of the pressure chamber plate 50 opposite to the side where the diaphragm assembly 40 is bonded, and the nozzle plate 54 is bonded. To do. A water repellent film 56 is formed in advance on the outer surface of the nozzle plate 54. The water repellent film 56 can be formed by an appropriate method. Specifically, a hydrophobic resin such as a fluorine-based resin may be formed by a vapor deposition method or the like.

  In the diaphragm assembly 40, as shown in FIGS. 10A to 10D, after the diaphragm 4 is bonded to the pressure chamber plate 50, the copper foil 4B is patterned and etched into a predetermined pattern, and then The pressure chamber 8 can be formed after the piezoelectric element 6 is bonded. When the copper foil 4B is patterned and etched, the region of the copper foil 4B has a larger area than the pressure chamber 8, and further exists from the inside to the outside of the pressure chamber. Thereby, since the periphery of the area | region of the copper foil 4B is located in the outer side of the pressure chamber 8, if the piezoelectric element 6 deform | transforms with a drive voltage, the diaphragm 4 whole will deform | transform.

  In addition, as shown in FIGS. 11A to 11C, the diaphragm 4 is bonded to the pressure chamber plate 50, the copper foil 4B is patterned and etched into a predetermined pattern, and then a gold plating layer is formed on the copper foil 4B. 4C is provided, and then, as shown in (D) in the figure, the portion of the surface of the metal plating layer 4C where the piezoelectric element 6 is not formed is masked, and piezoelectric ceramic is sputtered as shown in (E), and the masking is performed. May be removed to form the piezoelectric element 6. By forming the piezoelectric element 6 by sputtering, the piezoelectric element 6 that is thinner than the conventional one or the piezoelectric element 6 having a complicated shape can be easily manufactured.

  In addition to the features of the ink jet recording head according to the first embodiment, the ink jet recording head 200 according to the second embodiment has a simple structure of the pressure chamber plate 50 and the flow path plate 52, thereby reducing the number of components and the number of processes. Therefore, the cost can be easily reduced.

  Furthermore, the drive IC is usually mounted on the polyimide resin film 42B side of the electrode assembly 42. However, since the drive IC can be configured to be adjacent to the ink supply liquid chamber 60, the amount of heat generated by the drive IC. Even in the case where the drive IC is large, the drive IC can be effectively cooled by the ink flowing through the ink supply liquid chamber 60.

  The liquid droplet ejection apparatus of the present invention can be used not only as an ink jet recording apparatus that ejects ink onto a sheet of paper but also as a circuit printing apparatus that prints a circuit on a substrate.

FIG. 1 is a cross-sectional view illustrating the configuration of the ink jet recording head according to the first embodiment. FIG. 2 is a process diagram illustrating a process of joining a piezoelectric element to a diaphragm in a manufacturing procedure of a diaphragm assembly included in the ink jet recording head according to the first embodiment. FIG. 3 is a process diagram showing a procedure for producing an electrode assembly included in the diaphragm assembly of FIG. FIG. 4 is a process diagram showing a process of joining the electrode assembly shown in FIG. 3 to the diaphragm to which the piezoelectric element shown in FIG. 2 is joined. FIG. 5 is a process diagram illustrating another example of the process of bonding the piezoelectric element to the diaphragm. 6 is a process diagram showing a process of joining the electrode assembly shown in FIG. 3 to the diaphragm to which the piezoelectric element shown in FIG. 6 is joined. FIG. 7 is a cross-sectional view illustrating a configuration of the ink jet recording head according to the second embodiment. FIG. 8 is a process diagram illustrating a process of joining a piezoelectric element to a diaphragm in a manufacturing procedure of a diaphragm assembly provided in the ink jet recording head according to the second embodiment. FIG. 9 is a process diagram showing a process of bonding the diaphragm to which the piezoelectric element is bonded and the electrode assembly. FIG. 10 is a process diagram illustrating another example of the process of bonding the piezoelectric element to the diaphragm. FIG. 11 is a process diagram showing a procedure for forming a piezoelectric element on the diaphragm by sputtering. FIG. 12 is a graph showing the relationship between the pressure chamber area and the resonance frequency for a diaphragm in which copper foils or stainless foils having different thicknesses and a polyimide film are bonded together. FIG. 13 is a graph showing the relationship between the pressure chamber area and the amount of displacement for a diaphragm in which copper foils or stainless foils having different thicknesses and a polyimide film are bonded together. FIG. 14 shows a diaphragm in which a copper foil or stainless foil having a different thickness is bonded to a polyimide film, and a diaphragm in which a pressure chamber area, a stainless foil having a thickness of 20 μm and a polyimide film having a thickness of 1 μm are bonded. It is a graph which shows the relationship with the ratio of the displacement amount with respect to. FIG. 15 shows the thickness of the polyimide film and the maximum displacement when the thickness of the polyimide film to be bonded is changed in the vibration half in which the copper foil and the polyimide film are bonded to each other with a thickness of 9 μm. It is a graph which shows the relationship. FIG. 16 shows the relationship between the thickness of the polyimide film and the resonance frequency when the thickness of the polyimide film to be bonded is changed in the vibration half in which the copper foil and the polyimide film are bonded to each other. It is a graph which shows a relationship. FIG. 17 shows the displacement amount of a piezoelectric element (piezo element) and the maximum displacement amount when the displacement amount is 0 for a vibration plate in which copper foils or stainless foils having different thicknesses are bonded to a polyimide film. It is a graph which shows the relationship with the magnitude | size of the largest displacement amount with respect to the said deviation | shift amount at the time.

Explanation of symbols

4 Diaphragm 4A Polyimide resin film 4B Copper foil 4C Gold plating layer 6 Piezoelectric element 8 Pressure chamber 10 Nozzle 12 Anisotropic conductive film 14 Epoxy resin adhesive 20 Channel assembly 21 Nozzle plate 22A Reservoir chamber plate 23 Damper plate 24A Communication Hole plate 24B Communication hole plate 25 Separation plate 26 Pressure chamber plate 27 Communication passage 28 Ink supply passage 29 Ink temporary storage chamber 30 Air damper 40 Vibration plate assembly 42 Electrode assembly 42A Individual electrode 42B Polyimide resin film 42C Resist resin layer 50 Pressure Chamber plate 52 Channel plate 54 Nozzle plate 56 Water repellent film 60 Ink supply liquid chamber 100 Inkjet recording head 200 Inkjet recording head

Claims (15)

A vibration plate used in a droplet discharge head for forming at least a part of a wall surface of a pressure chamber communicating with a nozzle by a vibration plate and vibrating the vibration plate to discharge a droplet from the nozzle,
A diaphragm comprising a metal layer and a resin layer, wherein the thickness of the resin layer is larger than the thickness of the metal layer.   The diaphragm according to claim 1, wherein the metal layer is a copper layer, and the resin layer is a polyimide resin layer.   The diaphragm according to claim 2, wherein the copper layer and the polyimide resin layer are formed by heating and pressure-bonding a copper foil and a polyimide resin film. The diaphragm according to any one of claims 1 to 3,
A piezoelectric element bonded to a metal layer in the diaphragm;
A drive electrode for applying a drive voltage to the piezoelectric element;
Among the drive electrodes, one of the drive electrodes is bonded to one surface of the piezoelectric element, and the other of the drive electrodes is bonded to the other surface of the piezoelectric element.   The diaphragm assembly according to claim 4, wherein one of the drive electrodes is formed by a metal layer in the diaphragm.   An electrode assembly formed by laminating a resin film and the other of the drive electrodes, wherein the other of the drive electrodes is bonded to the diaphragm with the electrode assembly sandwiched between the piezoelectric elements, 6. The diaphragm assembly according to claim 5, wherein the diaphragm assembly is electrically joined to the diaphragm. The diaphragm according to any one of claims 1 to 3, which forms at least a part of a wall surface of the nozzle, a pressure chamber communicating with the nozzle, a pressure chamber communicating with the nozzle, and the diaphragm. And a piezoelectric element that vibrates
The droplet discharge head, wherein the piezoelectric element is bonded to a metal layer side of the diaphragm. The support body in which the said nozzle and the pressure chamber were formed, and the diaphragm assembly of any one of Claims 5-7 joined to the surface of the said support body in which the pressure chamber was formed. ,
The droplet ejection head according to claim 7, wherein the diaphragm assembly is joined to the support on a surface of the diaphragm opposite to a side to which a piezoelectric element is joined.   The droplet discharge head according to claim 8, wherein a region bonded to the piezoelectric element in the metal layer of the diaphragm is plated with gold.   10. The droplet discharge head according to claim 8, wherein a region of the metal layer of the diaphragm has a larger area than the pressure chamber and is formed from the inside to the outside of the pressure chamber.   A droplet discharge head according to any one of claims 7 to 10, a drive IC that drives a piezoelectric element included in the droplet discharge head, and a discharge liquid to be discharged from a nozzle of the droplet discharge head. A droplet discharge apparatus comprising discharge liquid supply means for supplying the pressure chamber of the droplet discharge head. The droplet discharge head includes a support body on which the pressure chamber is formed, and a diaphragm assembly according to claim 6 joined to a surface of the support body on which the pressure chamber is formed.
The diaphragm assembly is joined to the support on the surface of the diaphragm opposite to the side on which the piezoelectric element is joined,
The droplet discharge device according to claim 11, wherein the driving IC is mounted on a surface of the diaphragm assembly opposite to a side bonded to the support.   The liquid droplet ejection apparatus according to claim 11, wherein the liquid droplet ejection head is provided over the entire width of a print width that is a width printed by the liquid droplet ejection apparatus.   The discharge liquid supply means includes a discharge liquid supply chamber provided adjacent to a side of the diaphragm assembly opposite to a side bonded to the support, and the discharge liquid passing through the diaphragm assembly. The droplet discharge device according to claim 12, further comprising a discharge liquid supply flow path that communicates the supply chamber and the pressure chamber.   The droplet discharge device according to claim 11, wherein the discharge liquid is ink.

Images