JP5477015B2 - Inkjet head - Google Patents

Description

  The present invention relates to an ink-jet head, and more particularly, to an ink-jet head that is constituted by a laminated body composed of a plurality of layers and in which pressure chambers are arranged at high density in two upper and lower stages.

  Inkjet printers capable of high-definition drawing are desired for light printing applications, and high integration of inkjet heads is a market need.

  The inkjet head uses a piezoelectric element such as PZT that converts electrical signals into mechanical energy as pressure generating means for ejecting ink from the nozzles, and a diaphragm formed on one surface of the pressure chamber is vibrated by the piezoelectric element. Thus, it is known that the ink in the pressure chamber is changed in pressure for discharging from the nozzle. Unlike the thermal method, which uses a heater that converts electrical signals into thermal energy to change the pressure for ejection to the ink in the pressure chamber, the pressure chamber needs to be large, so it is physically integrated. There is a limit.

  For this reason, conventionally, there has been proposed a technique that enables high-pressure integration of pressure chambers by stacking the pressure chambers in two stages in the vertical direction (Patent Documents 1 and 2).

JP 2001-146010 A JP 2005-153001 A

  By the way, the ink jet head is provided with a throttle portion in an ink supply path for supplying ink to the pressure chamber.

  Such a narrowing portion adjusts the flow resistance on the ink supply path side in droplet ejection by partially narrowing the flow path of the ink supply path that supplies ink to the pressure chamber. Therefore, the narrowed portion is an important part for efficiently ejecting liquid droplets, and requires processing accuracy without variations.

  However, when the processing accuracy is increased, there is a problem that it takes time to process the drawn portion, and the cost for manufacturing a mask necessary for processing the drawn portion is increased.

  Since such a throttle portion is provided for each pressure chamber, when the pressure chambers are stacked in two upper and lower stages like the ink jet heads described in Patent Documents 1 and 2, the throttle portion also corresponds to the pressure chamber. Divided into different layers in two stages. Therefore, high-precision processing must be performed for each different layer in which the aperture is arranged, and processing time and processing are time-consuming, and the labor for mask manufacturing also takes time for each layer. There is a problem that the labor and cost are excessive.

  Therefore, an object of the present invention is to provide an inkjet head capable of suppressing the processing time and processing cost of the throttle portions respectively corresponding to the pressure chambers arranged in two upper and lower stages.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

The invention according to claim 1 is an ink jet head that is constituted by a laminated body composed of a plurality of layers, and that discharges ink in a pressure chamber provided in the laminated body from a nozzle by pressure generating means,
A first restricting portion provided in a first ink supply path communicating with a first pressure chamber formed in a first layer constituting the laminate;
A second throttle portion provided in a second ink supply path communicating with a second pressure chamber formed in a second layer constituting the laminate,
The first throttle part and the second throttle part are both formed in the same layer in the laminate ,
A common ink chamber for supplying ink to the first pressure chamber and the second pressure chamber in common via the first ink supply path and the second ink supply path is provided above the stacked body. And
The first layer is disposed above the second layer, and the second ink supply path passes through the first layer;
The first aperture portion and the second aperture portion are both formed in the first layer .

The invention according to claim 2 is an inkjet head that is constituted by a laminated body composed of a plurality of layers, and that ejects ink in a pressure chamber provided in the laminated body from a nozzle by a pressure generating means,
A first restricting portion provided in a first ink supply path communicating with a first pressure chamber formed in a first layer constituting the laminate;
A second throttle portion provided in a second ink supply path communicating with a second pressure chamber formed in a second layer constituting the laminate,
The first throttle part and the second throttle part are both formed in the same layer in the laminate,
The ink-jet head is characterized in that the first diaphragm portion is arranged in a horizontal direction and the second diaphragm portion is arranged in a vertical direction .

Third aspect of the present invention, the first diaphragm portion is disposed sideways, the second diaphragm portion is an ink jet head according to claim 1 Symbol mounting, characterized in that it is arranged vertically.

Fourth aspect of the present invention, the first diaphragm portion and the second diaphragm portion is an ink jet head according to claim 1 Symbol mounting, characterized in that are both arranged vertically.

The invention according to claim 5 is characterized in that the first layer is a Si layer, and the first pressure chamber, the first throttle part, and the second throttle part are processed by etching. The inkjet head according to any one of claims 1 to 4 .

  According to the present invention, it is possible to provide an ink jet head capable of suppressing the processing time and processing cost of the throttle portion by providing the throttle portions corresponding to the pressure chambers arranged in the upper and lower stages in the same layer. .

1 is a partial cross-sectional view illustrating a layer configuration of an inkjet head according to a first embodiment of the present invention. Plane perspective view showing the arrangement configuration of the pressure chambers in the vertical direction in the first embodiment The fragmentary sectional view showing the layer composition of the ink jet head concerning the 2nd embodiment of the present invention. Plane see-through | perspective view which shows the arrangement structure of the up-down direction of the pressure chamber in 2nd Embodiment

  The present invention is an ink jet head that is constituted by a laminated body composed of a plurality of layers and that discharges ink in a pressure chamber provided in the laminated body from a nozzle by a pressure generating means, and includes a first body constituting the laminated body. A first throttle portion provided in a first ink supply path communicating with the first pressure chamber formed in the layer, and a second pressure chamber formed in the second layer constituting the laminate. A second diaphragm provided in a second ink supply path that communicates, and both the first diaphragm and the second diaphragm are formed in the same layer in the laminate. It is characterized by being.

  The fact that both the first throttle part and the second throttle part are formed in the same layer in the stacked body means that all the first throttle parts and all the second throttle parts are formed in one common layer in the stacked body. The aperture portion is formed.

  The first pressure chamber and the second pressure chamber are arranged in a matrix in a planar manner in each of the first layer and the second layer of the plurality of layers constituting the stacked body. Therefore, the density and size of the ink jet head can be reduced.

  In addition, since the first and second diaphragms that require high processing accuracy are provided in the same layer in the laminate, the first and second diaphragms are provided. Can be processed on the same layer at once. Therefore, the processing time for processing all the narrowed portions can be greatly reduced.

  In the inkjet head according to the present invention, common ink is supplied to the first pressure chamber and the second pressure chamber via the first ink supply path and the second ink supply path to the upper portion of the laminate. Has a room. That is, the first ink supply path and the second ink supply path are both opened on the upper surface of the laminate so as to face the common ink chamber. The first layer is disposed above the second layer, and the second ink supply path passes through the first layer. It is preferable that both the first throttle part and the second throttle part are formed in the first layer.

  As a result, the second restricting portion provided in the second ink supply path that penetrates the first layer can be a simple through-hole having a partially reduced diameter. It can be processed easily and with high accuracy.

  In addition, since it is not necessary to process the drawn portion in the second layer, a simple processing method can be selected for the second layer. This is because, generally, higher processing accuracy is required for processing of the drawn portion than for processing of the pressure chamber. For this reason, it becomes possible to hold down processing cost.

  In the inkjet head according to the present invention, the side from which ink is ejected from the nozzle is defined as the lower side, and the opposite side is defined as the upper side. Therefore, in the laminate constituting the ink jet head, a layer disposed on the upper side with respect to a reference layer is referred to as an upper layer, and a layer disposed on the lower side is referred to as a lower layer. However, the first layer and the second layer are not necessarily in contact with each other.

  As an aspect of the first diaphragm section and the second diaphragm section, the first diaphragm section is disposed sideways and the second diaphragm section is disposed vertically, the first diaphragm section and the second diaphragm section. A mode in which the diaphragm portions are both arranged vertically is exemplified.

  Here, the horizontal direction and the vertical direction refer to the direction of the flow of ink respectively flowing toward the first pressure chamber and the second pressure chamber. Accordingly, the horizontal direction means that the ink flows laterally toward the pressure chamber in the throttle portion, and the vertical direction means the ink is vertical (from top to bottom) toward the pressure chamber in the throttle portion. It means to flow through.

  According to the former aspect, by setting the first throttle portion sideways, the corners to the first pressure chamber can be reduced, and cavitation due to the pressure difference can be prevented. Moreover, according to the latter aspect, the area occupied by the first throttle portion can be greatly reduced, and the pressure chamber can be highly integrated.

  In the present invention, the first layer is a Si (silicon) layer, and the first pressure chamber, the first throttle portion, and the second throttle portion formed in the first layer are processed by etching. It is preferable. This is because the etching process for the Si layer can be performed with high accuracy by the RIE (Reactive Ion Etching) method.

  Next, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a partial cross-sectional view showing a layer structure of an ink jet head according to the first embodiment of the present invention, and FIG. 2 is a plan perspective view showing an arrangement structure of pressure chambers in the vertical direction.

  As shown in FIG. 1, the inkjet head 1 is configured by a laminated body in which a plurality of layers are laminated. In the present embodiment, the body layer 10 at the center of the layer, the first silicon interposer layer 20 on the upper layer side of the body layer 10, and the second silicon interposer layer 30 and the nozzle plate layer 40 on the lower layer side are provided. .

  The body layer 10 has Si (silicon) layers 12 and 13 laminated on an upper layer and a lower layer, respectively, with a central glass layer 11 interposed therebetween, and are integrally bonded by anodic bonding.

  The Si layer 12 on the upper layer side is the first layer in the present invention, and the first pressure chamber 121 recessed by etching by the RIE method from the lower surface side in the drawing in contact with the glass layer 11 is horizontal. Many arrays are formed in a matrix in the direction. The upper wall of the first pressure chamber 121 constitutes a diaphragm 122 in which the Si layer 12 is formed thin. On the upper surface side of the diaphragm 122, piezoelectric elements 123 such as PZT as pressure generating means are respectively provided. Are stacked.

  On the other hand, the Si layer 13 on the lower layer side is the second layer in the present invention, and the second pressure chamber 131 recessed by etching by the RIE method from the upper surface side in the drawing in contact with the glass layer 11 is provided. Many arrays are formed in a matrix in the horizontal direction. The upper wall of the first pressure chamber 131 constitutes a diaphragm 132 in which the Si layer 13 is formed thin. On the lower surface side of the diaphragm 132, piezoelectric elements 133 such as PZT as pressure generating means are respectively provided. Are stacked.

  The first pressure chamber 121 and the second pressure chamber 131 are three-dimensionally arranged in two layers in the vertical direction in the figure, which is the stacking direction, and partially overlap each other in plan view as shown in FIG. It is arranged to wrap. For this reason, the spread of the first pressure chamber 121 and the second pressure chamber 131 in the horizontal direction is suppressed, and the density is increased.

The first silicon interposer layer 20 includes a Si (silicon) layer 21, an insulating layer 22, and a photosensitive adhesive layer 23 in order from the top. The insulating layer 22 is made of a SiO ₂ film, and a piezoelectric element in which the rear end is electrically connected to a drive circuit (not shown) in the layer and an electric signal from the drive circuit is stacked in the first pressure chamber 121. A wiring 221 for applying to 123 is provided. One end of the wiring 221 is formed of, for example, low melting point solder, protrudes downward from the insulating layer 22 and is exposed outside the layer, and forms a contact portion 222 that is electrically connected to the electrode of the piezoelectric element 123. The photosensitive adhesive layer 23 has a concave portion 231, and the contact portion 222 and the piezoelectric element 123 are accommodated in the concave portion 231.

The second silicon interposer layer 30 includes a photosensitive adhesive layer 31, an insulating layer 32, a Si (silicon) layer 33, and a photosensitive adhesive layer 34 in order from the top. The insulating layer 32 is made of an SiO ₂ film, and a piezoelectric element in which the rear end is electrically connected to a drive circuit (not shown) in the layer and an electric signal from the drive circuit is stacked in the second pressure chamber 131. A wiring 321 for applying to 133 is provided. One end of the wiring 321 is formed of, for example, low melting point solder, protrudes upward from the insulating layer 32 and is exposed outside the layer, and forms a contact portion 322 electrically connected to the electrode of the piezoelectric element 133. The photosensitive adhesive layer 31 has a recess 311, and the contact portion 322 and the piezoelectric element 133 are accommodated in the recess 311.

  The nozzle plate layer 40 is made of Si, and the nozzle 41 corresponding to the first pressure chamber 121 and the nozzle 42 corresponding to the second pressure chamber 131 are etched by the RIE method.

  The first ink supply path 50 communicating with the inside of the first pressure chamber 121 penetrates in the vertical direction from the Si layer 21 of the first interposer layer 20 which is the uppermost layer of the inkjet head 1 to the Si layer 12 of the body layer 10. It is formed to do. The first ink supply path 50 is bent laterally in the Si layer 12 of the body layer 10, and supplies ink in the lateral direction into the first pressure chamber 121 in the Si layer 12. . The lateral flow path portion 52 in the Si layer 12 in the first ink supply path 50 is formed narrower than the flow path diameter of the vertical flow path section 51 in the first ink supply path 50, and the ink The horizontal first narrowed portion 52 in which the flow path is partially narrowed is formed.

  Also, a first ink discharge path 60 is formed so as to penetrate in the vertical direction from the glass layer 11 of the body layer 10 through the Si layer 13 to the photosensitive adhesive layer 34 of the second interposer layer 30. The pressure chamber 121 communicates with the nozzle 41 formed on the nozzle plate layer 40.

  The second ink supply path 70 communicating with the inside of the second pressure chamber 131 extends from the Si layer 21 of the first interposer layer 20, which is the uppermost layer of the inkjet head 1, to the Si layer 12 and the glass layer 11 of the body layer 10. It is formed so as to penetrate in the vertical direction. The lower end of the second ink supply path 70 opens into the second pressure chamber 131 that is recessed in the Si layer 13, and supplies ink in the vertical direction to the second pressure chamber 131. It is like that. The vertical flow path portion 72 in the Si layer 12 in the second ink supply path 70 is formed of the vertical flow path section 71 and the glass penetrating the first interposer layer 20 in the second ink supply path 70. A vertical second narrowing portion 72 is formed which is formed to have a diameter smaller than the flow path diameter of the vertical flow path portion 73 penetrating the layer 11 and partially narrows the ink flow path.

  Further, a second ink discharge path 80 is formed so as to penetrate in the vertical direction from the Si layer 13 of the body layer 10 to the photosensitive adhesive layer 34 of the second interposer layer 30. The nozzles 42 formed in the nozzle plate layer 40 are communicated with each other.

  A common ink chamber (not shown) is provided on the upper surface of the uppermost Si layer 21. The first ink supply path 50 and the second ink supply path 70 are opened to face the common ink chamber, and the ink is shared from the common ink chamber to the first pressure chamber 121 and the second pressure chamber 131. Is to be supplied.

  In the first embodiment illustrated above, ink is supplied to the first throttle portion 52 provided in the first ink supply path 50 that supplies ink to the first pressure chamber 121 and the second pressure chamber 131. Since the second diaphragm 72 provided in the second ink supply path 70 is provided in the Si layer 12 (first layer) which is the same layer, extremely high processing accuracy is achieved. The required processing of the first drawing unit 52 and the second drawing unit 72 can be processed only for the Si layer 12 at a time, and the processing time for processing all the drawing units is greatly reduced. be able to.

  In addition, since the processing of the first drawing portion 52 and the second drawing portion 72 is processing for Si, highly accurate etching can be performed by the RIE method. In addition, since it is not necessary to process the throttle portion in the Si layer 13 of the second pressure chamber 131 for the second pressure chamber 131, a simple processing method can be selected for the second pressure chamber 131. Therefore, the processing cost can be suppressed.

  FIG. 3 is a partial cross-sectional view showing a layer configuration of an ink jet head according to the second embodiment of the present invention, and FIG. 3 is a plan perspective view showing an arrangement configuration of pressure chambers in the vertical direction. The parts denoted by the same reference numerals as those in FIGS. 1 and 2 indicate the parts having the same configuration, and thus detailed description thereof is omitted here.

  In the inkjet head 100 according to the present embodiment, the first ink supply path 50 that supplies ink from the common ink chamber to the first pressure chamber 121 is Si of the first interposer layer 20 that is the uppermost layer of the inkjet head 1. This is the same as in the first embodiment in that it is formed so as to penetrate from the layer 21 to the Si layer 12 of the body layer 10 in the vertical direction. A through-hole 53 penetrating the layer 12 in the vertical direction is formed with a diameter smaller than the channel diameter of the channel portion 51 penetrating the first interposer layer 20 in the first ink supply path 50 in the vertical direction. The difference is that the first narrowed portion 53 is formed in the vertical direction in which the path is partially narrowed. On the upper surface of the glass layer 11 in contact with the Si layer 12, a groove-shaped channel portion 54 is formed, and the lower end of the first throttle portion 53 formed of this through hole and the first pressure chamber 121 are formed. And communicate with.

  Also in the second embodiment, ink is supplied to the first throttle portion 53 provided in the first ink supply path 50 that supplies ink to the first pressure chamber 121 and the second pressure chamber 131. Since the second diaphragm 72 provided in the second ink supply path 70 is provided in the Si layer 12 (first layer) which is the same layer, extremely high processing accuracy is required. Since the first throttle part 53 and the second throttle part 72 to be processed can be processed only for the Si layer 12 at a time, and since it has a simple through-hole shape, all the throttle parts The processing time for processing can be greatly reduced.

  In addition, since the processing of the first drawing portion 53 and the second drawing portion 72 is processing for Si, high-precision etching can be performed by the RIE method. In addition, since it is not necessary to process the throttle portion in the Si layer 13 of the second pressure chamber 131 for the second pressure chamber 131, a simple processing method can be selected for the second pressure chamber 131. Therefore, the processing cost can be suppressed.

1, 100: inkjet head 10: body layer 11: glass layer 12: Si layer (first layer)
121: first pressure chamber 122: diaphragm 123: piezoelectric element 13: Si layer (second layer)
131: second pressure chamber 132: diaphragm 133: piezoelectric element 20: first interposer layer 21: Si layer 22: insulating layer 221: wiring 222: contact portion 23: photosensitive adhesive layer 231: recess 30: first 2 interposer layer 31: photosensitive adhesive layer 311: concave portion 32: insulating layer 321: wiring 322: contact portion 33: Si layer 34: photosensitive adhesive layer 40: nozzle plate layer 41, 42: nozzle 50: first Ink supply path 51: Vertical flow path portion 52: First restricting portion (horizontal flow path portion)
53: First restricting portion (through hole)
54: concave groove-shaped flow path portion 60: first ink discharge path 70: second ink supply path 71: vertical flow path section 72: second throttle section (vertical flow path section)
73: Vertical flow path portion 80: Second ink discharge path

Claims (5)

An ink jet head configured by a laminated body composed of a plurality of layers, wherein the ink in a pressure chamber provided in the laminated body is ejected from a nozzle by a pressure generating means;
A first restricting portion provided in a first ink supply path communicating with a first pressure chamber formed in a first layer constituting the laminate;
A second throttle portion provided in a second ink supply path communicating with a second pressure chamber formed in a second layer constituting the laminate,
The first throttle part and the second throttle part are both formed in the same layer in the laminate ,
A common ink chamber for supplying ink to the first pressure chamber and the second pressure chamber in common via the first ink supply path and the second ink supply path is provided above the stacked body. And
The first layer is disposed above the second layer, and the second ink supply path passes through the first layer;
The ink jet head according to claim 1, wherein the first aperture portion and the second aperture portion are both formed in the first layer . An ink jet head configured by a laminated body composed of a plurality of layers, wherein the ink in a pressure chamber provided in the laminated body is ejected from a nozzle by a pressure generating means;
A first restricting portion provided in a first ink supply path communicating with a first pressure chamber formed in a first layer constituting the laminate;
A second throttle portion provided in a second ink supply path communicating with a second pressure chamber formed in a second layer constituting the laminate,
The first throttle part and the second throttle part are both formed in the same layer in the laminate ,
The inkjet head according to claim 1, wherein the first aperture portion is disposed in a horizontal direction, and the second aperture portion is disposed in a vertical direction . Wherein the first diaphragm portion is disposed sideways, the second is the throttle portion according to claim 1 Symbol placement inkjet head, characterized in that it is arranged vertically. Wherein the first diaphragm portion and the claim 1 Symbol mounting the ink jet head of the second diaphragm portion, characterized in that it is co-located vertically. Wherein the first layer is a Si layer, the first pressure chamber, one of claims 1 to 4, wherein the first diaphragm portion and the second diaphragm portion is characterized in that it is processed by etching inkjet head crab according.

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