JP2020023197A - Flow path component, liquid discharge head and liquid discharge device - Google Patents

Abstract

To provide a flow path component, a liquid discharge head and a liquid discharge device which can secure a necessary length of an individual communication port.SOLUTION: In a second liquid chamber 52 of a communication substrate 23 is formed an inclined surface 41 inclined from a lower surface of a ceiling part 40, that is, a ceiling surface of the second liquid chamber, toward a lower surface of the communication substrate, and is further formed an individual communication port 42 penetrating through the communication substrate from the inclined surface. One end (a lower end) of the individual communication port opens to the inclined surface and communicates with the second liquid chamber, and the other end (an upper end) of the individual communication port opens to the upper surface of the communication substrate and communicates individually with a pressure chamber of a pressure chamber forming substrate. When a thickness of the communication substrate is defined as T, a length of the individual communication port is defined as L and a substantial depth of the second liquid chamber is defined as D, a relational expression of L+D>T is satisfied.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a flow path component used for a liquid discharge head such as an ink jet recording head and a liquid discharge apparatus, and particularly to a flow path component formed from a silicon substrate, a liquid discharge head, and a liquid discharge head. Related to the device.

  The liquid discharge device is a device that includes a liquid discharge head and discharges (ejects) various liquids from the discharge head. Examples of the liquid ejecting apparatus include image recording apparatuses such as an ink jet printer and an ink jet plotter. Recently, various types of liquid ejecting apparatuses have been manufactured by taking advantage of a feature that a very small amount of liquid can be accurately landed at a predetermined position. It is also applied to equipment. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or an FED (surface emitting display), and a chip for manufacturing a biochip (biochemical element). It is applied to manufacturing equipment. A recording head for an image recording apparatus discharges a liquid ink, and a color material discharge head for a display manufacturing apparatus discharges a solution of each of R (Red), G (Green), and B (Blue) color materials. In addition, the electrode material discharge head for the electrode forming apparatus discharges a liquid electrode material, and the biological organic substance discharge head for the chip manufacturing apparatus discharges a solution of a biological organic substance.

  This type of liquid ejection head includes, for example, a nozzle plate having a plurality of nozzles, a substrate having a plurality of vacant spaces serving as pressure chambers communicating with each nozzle, and a common liquid storing a common liquid in each pressure chamber. Some include a substrate on which a flow path space that is a liquid chamber (also referred to as a reservoir or a manifold) is formed, a plurality of piezoelectric elements (a type of actuator) provided corresponding to each pressure chamber, and the like. In this configuration, since a flow path and the like can be formed with high accuracy by etching, a silicon substrate (silicon single crystal substrate) is used as a material of a substrate for forming the flow path ( For example, see Patent Document 1).

  In the configuration disclosed in the above-mentioned Patent Document 1, as shown in FIG. 12, in the communication substrate 64 in which the passage space of the common liquid chamber is formed, the substrate is arranged from the lower surface of the communication substrate 64 to the upper surface side. An empty portion (hereinafter, referred to as a liquid chamber empty portion) 65 which becomes a part of the common liquid chamber by being depressed by etching to a part in the thickness direction is formed. The communication substrate 64 is provided with an individual communication port 66 penetrating from the common liquid chamber to the upper surface of the communication substrate in order to individually communicate the common liquid chamber and each pressure chamber. The individual communication port 66 functions as a flow path for individually supplying ink from the common liquid chamber side to the pressure chamber, and is a part related to ejection efficiency when ejecting ink from the nozzle by driving the actuator. For this reason, the flow path cross-sectional area (hole diameter) and the flow path length are designed so that the flow resistance and the inertance at the individual communication port 66 are appropriate. Since the minimum value of the hole diameter X of the individual communication port 66 is determined to some extent according to the processing method, generally, the above-mentioned inertance becomes an appropriate value after the hole diameter X is fixed. As described above, the overall length L 'of the individual communication port 66 is mainly adjusted.

JP 2014-031333 A

  However, if the length L 'of the individual communication port 66 is appropriately set, the depth D of the liquid chamber empty space 65 tends to be reduced accordingly, that is, the flow path cross-sectional area of the liquid chamber empty space 65 becomes small. Therefore, the flow path resistance in the liquid chamber empty space 65 increases, and the pressure loss tends to increase. Conversely, when the depth D of the liquid chamber space 65 is secured to suppress the pressure loss, the length L 'of the individual communication port 66 is insufficient.

  The present invention has been made in view of such circumstances, and a purpose thereof is to provide a flow path component, a liquid discharge head, and a liquid discharge device that can secure a required length of an individual communication port. To provide.

The flow path component of the present invention has been proposed in order to achieve the above object, and is formed by being depressed halfway in the thickness direction from the first surface of the silicon substrate to the second surface on the opposite side. Flow path space,
Having an individual flow channel penetrating the silicon substrate from the flow channel space to the second surface side,
The sum of the length L of the individual flow path and the substantial depth D of the flow path space in the thickness direction of the silicon substrate is larger than the thickness T of the silicon substrate.

  According to the present invention, the sum of the length L of the individual flow channel and the substantial depth D of the channel space in the thickness direction of the silicon substrate is larger than the thickness of the silicon substrate. In addition, the required depth D of the channel empty space and the required length L of the individual flow channel can both be ensured. Therefore, while the flow resistance and the inertance of the individual flow paths can be appropriately adjusted, the required depth of the flow path vacancies can be secured, so that the pressure loss in the flow path vacancies can be suppressed.

Further, in the above-described configuration, the channel space has an inclined surface inclined from the bottom surface on the second surface side toward the first surface,
It is desirable to adopt a configuration in which one end of the individual flow path is opened to the inclined surface.

According to this configuration, the length L of the individual flow path is arbitrary, that is, the necessary length is adjusted by adjusting the opening position of the individual flow path on the inclined surface without being affected by the depth D of the flow path space. L can be set. Therefore, the flow resistance and inertance of the individual flow paths can be appropriately adjusted. On the other hand, as for the channel space, the required depth D can be ensured without being affected by the length L of the individual channel, so that the pressure loss in the channel space can be suppressed. By adopting such a configuration, even if the thickness of the flow path component tends to become thinner, the required length L of the individual flow path and the required depth D of the flow path empty space are ensured. Therefore, it is possible to cope with downsizing of the liquid ejection head on which the flow path component is mounted.
In addition, by providing a slope in the channel space and opening one end of the individual channel on the slope, the channel cross-sectional area of the channel space gradually narrows toward the individual channel. It takes shape. Thereby, the flow velocity of the liquid flowing toward the individual flow path is increased. Thereby, the discharge property of the air bubbles in the channel space can be improved.

Further, in the above configuration, the silicon substrate is a substrate having the first surface and the second surface as (110) surfaces,
It is preferable that the inclined surface adopts a configuration composed of a (111) plane inclined with respect to the (110) plane.

  According to this configuration, by forming the (111) plane generated when the channel space is formed by anisotropic etching as the inclined surface, the inclined surface can be formed without additional steps.

Further, in the above configuration, the relationship between the distance d from the end of the individual channel side in the channel empty portion to the center axis of the individual channel and the substantial depth D of the channel empty portion is as follows. Formula d ≦ 1.73D
It is desirable to satisfy

  According to this configuration, the formation position of the individual channel can be appropriately determined based on the required depth D of the channel space.

Further, the liquid discharge head of the present invention, the flow path component of any of the above configuration,
A pressure chamber forming member in which a pressure chamber communicating with the nozzle is formed,
With
The individual flow path communicates with the pressure chamber,
The liquid from the flow channel space is supplied to the pressure chamber through the individual flow channel.

  According to the present invention, the length L of the individual flow path is arbitrary, that is, the required length is adjusted by adjusting the opening position of the individual flow path on the inclined surface without being affected by the depth D of the flow path space. L can be set. For this reason, the flow path resistance and inertance of the individual flow paths can be appropriately adjusted. On the other hand, as for the channel space, the required depth D can be ensured without being affected by the length L of the individual channel, so that the pressure loss in the channel space can be suppressed. By adopting such a configuration, even if the thickness of the flow path component tends to become thinner, the required length L of the individual flow path and the required depth D of the flow path empty space are ensured. Therefore, it is possible to cope with the miniaturization of the liquid discharge head without lowering the liquid discharge efficiency and the like.

According to another aspect of the invention, there is provided a liquid ejection apparatus including the above liquid ejection head.
Furthermore, the present invention proposed to achieve the above object may have the following configuration.
That is, a flow path component that is joined to a member in which a plurality of pressure chambers respectively communicating with a plurality of nozzles are formed,
A flow path void formed to be depressed halfway in the thickness direction from the first surface of the silicon substrate toward the opposite second surface, and provided in common to the plurality of pressure chambers;
Having an individual flow path that is individually provided for each of the pressure chambers, penetrating the silicon substrate from the flow path space to the second surface side,
The flow path void has a bottom surface extending parallel to the second surface, and an inclined surface inclined from the bottom surface toward the first surface,
One end of the individual flow path opens on the inclined surface,
The sum of the length L of the individual flow channel and the depth D from the first surface to the bottom surface of the flow channel space in the thickness direction of the silicon substrate is larger than the thickness T of the silicon substrate,
The relationship between the distance d from the end of the individual channel side in the channel empty portion to the central axis of the individual channel and the depth D from the first surface to the bottom surface of the channel empty portion is as follows: Formula d ≦ 1.73D
Is satisfied.
According to the present invention, the sum of the length L of the individual flow channel and the depth D from the first surface to the bottom surface of the flow channel space in the thickness direction of the silicon substrate is larger than the thickness of the silicon substrate. By doing so, it is possible to ensure both the required depth D of the channel empty space and the required length L of the individual channel. Therefore, while the flow resistance and the inertance of the individual flow paths can be appropriately adjusted, the required depth of the flow path vacancies can be secured, so that the pressure loss in the flow path vacancies can be suppressed.
Further, the length L of the individual flow channel is set to an arbitrary value, that is, a required length L by adjusting the opening position of the individual flow channel on the inclined surface without being affected by the depth D of the flow channel space. can do. For this reason, the flow path resistance and inertance of the individual flow paths can be appropriately adjusted. On the other hand, as for the channel space, the required depth D can be ensured without being affected by the length L of the individual channel, so that the pressure loss in the channel space can be suppressed. By adopting such a configuration, even if the thickness of the flow path component tends to become thinner, the required length L of the individual flow path and the required depth D of the flow path empty space are ensured. Therefore, it is possible to cope with downsizing of the liquid ejection head on which the flow path component is mounted.
Furthermore, by providing an inclined surface in the channel space and opening one end of the individual channel on the inclined surface, the flow path cross-sectional area of the channel space gradually narrows toward the individual channel. It takes shape. Thereby, the flow velocity of the liquid flowing toward the individual flow path is increased. Thereby, the discharge property of the air bubbles in the channel space can be improved.
In addition, according to the configuration, the formation position of the individual flow channel can be appropriately determined based on the required depth D of the flow channel space.
In the above configuration, the silicon substrate is a substrate having the first surface and the second surface as (110) surfaces,
It is preferable that the inclined surface adopts a configuration composed of a (111) plane inclined with respect to the (110) plane.
According to this configuration, by forming the (111) plane generated when the channel space is formed by anisotropic etching as the inclined surface, the inclined surface can be formed without additional steps.
Further, the liquid ejection head of the present invention, the flow path component of any of the above configuration,
A pressure chamber forming member in which a pressure chamber communicating with the nozzle is formed,
With
The individual flow path communicates with the pressure chamber,
The liquid from the flow channel space is supplied to the pressure chamber through the individual flow channel.
According to the present invention, the length L of the individual flow path is arbitrary, that is, the required length is adjusted by adjusting the opening position of the individual flow path on the inclined surface without being affected by the depth D of the flow path space. L can be set. For this reason, the flow path resistance and inertance of the individual flow paths can be appropriately adjusted. On the other hand, as for the channel space, the required depth D can be ensured without being influenced by the length L of the individual channel, so that the pressure loss in the channel space can be suppressed. By adopting such a configuration, even if the thickness of the flow path component tends to be thinner, the required length L of the individual flow path and the required depth D of the flow path empty space are ensured. Therefore, it is possible to cope with the miniaturization of the liquid discharge head without reducing the liquid discharge efficiency and the like.
According to another aspect of the invention, there is provided a liquid ejection apparatus including the above-described liquid ejection head.

FIG. 2 is a perspective view illustrating an internal configuration of the printer. FIG. 3 is a sectional view of a recording head. FIG. 3 is an enlarged sectional view of a region A in FIG. 2. It is principal part sectional drawing near an individual communication port. It is a top view of a communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is a figure explaining the formation process of the 2nd liquid room and the individual communication port in the communication board. It is principal part sectional drawing near the individual communication port in the conventional structure.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Note that, in the embodiments described below, various limitations are given as preferred specific examples of the present invention, but the scope of the present invention is limited to the following description unless otherwise specified in the following description. It is not limited to these embodiments. In the following description, an ink jet printer (hereinafter, printer) equipped with an ink jet recording head (hereinafter, recording head), which is a kind of liquid ejection head, will be described as an example of the liquid ejection apparatus of the present invention.

  The configuration of the printer 1 will be described with reference to FIG. The printer 1 is a device that records an image or the like by discharging liquid ink onto the surface of a recording medium 2 such as recording paper. The printer 1 includes a recording head 3 for discharging ink, a carriage 4 to which the recording head 3 is attached, a carriage moving mechanism 5 for moving the carriage 4 in the main scanning direction, and a platen roller 6 for conveying the recording medium 2 in the sub-scanning direction. Etc. are provided. Here, the ink is a kind of liquid and is stored in the ink cartridge 7 as a liquid supply source. The ink cartridge 7 is detachably mounted on the recording head 3. Note that a configuration in which the ink cartridge 7 is arranged on the main body side of the printer 1 and is supplied from the ink cartridge 7 to the recording head 3 through an ink supply tube can also be adopted.

  FIG. 2 is a cross-sectional view illustrating a configuration of a main part of the recording head 3. FIG. 3 is an enlarged view of a region A in FIG. The recording head 3 according to the present embodiment includes a pressure generating unit 14 and a flow path unit 21, and is configured to be attached to a case 26 in a state where these members are stacked. The channel unit 21 has a nozzle plate 22, a compliance sheet 25, and a communication board 23 (corresponding to a channel component in the present invention). The pressure generating unit 14 is formed as a unit by laminating a pressure chamber forming substrate 29 in which a pressure chamber 31 is formed, an elastic film 30, a piezoelectric element 35 (actuator), and a protective substrate 24.

  The case 26 is a box-shaped member made of synthetic resin to which the communication board 23 to which the nozzle plate 22 and the pressure generating unit 14 are joined is fixed to the bottom side. A through-hole portion 44 having a long rectangular opening along the nozzle row direction is formed at the center of the case 26 in a plan view so as to penetrate the case 26 in the height direction. The through space 44 communicates with the wiring space 38 of the pressure generating unit 14 to form a space in which one end of the wiring member (flexible cable 49) and the drive IC 50 are housed. Further, on the lower surface side of the case 26, a storage space 47 which is recessed in a rectangular parallelepiped shape from the lower surface to halfway in the height direction of the case 26 is formed. When the flow path unit 21 is joined to the lower surface of the case 26 in a positioning state, the pressure generating units 14 stacked on the communication substrate 23 are housed in the housing space 47. The lower end of the through space 44 is open to the ceiling of the storage space 47.

  In the case 26, an ink introduction space 46 and an ink introduction passage 45 are formed. The ink introduction path 45 is a narrow flow path having a smaller cross-sectional area than the ink introduction empty space 46, and supplies ink from the ink cartridge 7 to the ink introduction empty space 46. The ink that has flowed into the ink introduction space 46 is introduced into a common liquid chamber 32 (described later) of the communication substrate 23.

  The pressure chamber forming substrate 29, which is a component of the pressure generating unit 14, is made of a silicon single crystal substrate (a kind of crystalline substrate; hereinafter, also simply referred to as a silicon substrate). In the pressure chamber forming substrate 29, vacancies (hereinafter, referred to as pressure chambers 31 including these vacancies) that become a plurality of pressure chambers 31 by anisotropic etching on a silicon substrate are formed in the nozzle plate 22. A plurality of nozzles are formed corresponding to the plurality of nozzles 27. As described above, by forming the pressure chamber on the silicon substrate by anisotropic etching, higher dimensional and shape accuracy can be secured. As will be described later, since the nozzle plate 22 in the present embodiment has two rows of nozzles 27 formed thereon, the pressure chamber forming substrate 29 has two rows of pressure chambers 31 corresponding to each nozzle row. Is formed. The pressure chamber 31 is a space that is long in a direction orthogonal to the nozzle row direction. When the pressure chamber forming substrate 29 is joined to the communication substrate 23 while being positioned, the longitudinal end of the pressure chamber 31 communicates with the nozzle 27 via a nozzle communication passage 36 of the communication substrate 23 described later. . The other end in the longitudinal direction of the pressure chamber 31 communicates with the common liquid chamber 32 via an individual communication port 42 (corresponding to an individual flow path in the present invention) of the communication substrate 23.

  An elastic film 30 is formed on the upper surface of the pressure chamber forming substrate 29 (the surface opposite to the bonding surface with the communication substrate 23) so as to seal the upper opening of the pressure chamber 31. The elastic film 30 is made of, for example, silicon dioxide having a thickness of about 1 μm. An insulating film (not shown) is formed on the elastic film 30. This insulating film is made of, for example, zirconium oxide. Then, a piezoelectric element 35 is formed at a position corresponding to each pressure chamber 31 on the elastic film 30 and the insulating film. The piezoelectric element 35 in the present embodiment is a so-called bending mode piezoelectric element. The piezoelectric element 35 includes a metal lower electrode film, a piezoelectric layer made of lead zirconate titanate (PZT), and a metal upper electrode film (all shown on the elastic film 30 and the insulating film). ) Are sequentially laminated, and then appropriately patterned for each pressure chamber 31. One of the upper electrode film and the lower electrode film is used as a common electrode, and the other is used as an individual electrode. In addition, the elastic film 30, the insulating film, and the lower electrode film function as a vibration plate when the piezoelectric element 35 is driven.

  From the individual electrodes (upper electrode films) of the respective piezoelectric elements 35, electrode wiring portions (not shown) extend into the wiring space portions 38, and flexible cable portions are provided at portions corresponding to the electrode terminals of these electrode wiring portions. The terminal on one end side of 49 is connected. A drive IC 50 for driving the piezoelectric element 35 is mounted on the surface of the flexible cable 49. Each piezoelectric element 35 bends and deforms when a drive signal (drive voltage) is applied between the upper electrode film and the lower electrode film through the drive IC 50.

  The protection substrate 24 is disposed on the upper surface of the communication substrate 23 on which the piezoelectric element 35 is formed. The protection substrate 24 is made of, for example, glass, ceramic material, silicon single crystal substrate, metal, synthetic resin, or the like. Inside the protection substrate 24, a recess 39 having a size that does not hinder the driving of the piezoelectric element 35 is formed in a region facing the piezoelectric element 35. Further, in the protection substrate 24, a wiring space 38 penetrating in the thickness direction of the substrate is formed between adjacent piezoelectric element rows. In the wiring space 38, an electrode terminal of the piezoelectric element 35 and one end of the flexible cable 49 are arranged.

  The nozzle plate 22 and the compliance sheet 25 are joined to the lower surface of the communication board 23. The nozzle plate 22 is a plate material in which a plurality of nozzles 27 are opened, and is joined to a central portion of the lower surface of the communication substrate 23 in a state where each nozzle 27 communicates with the nozzle communication passage 36 of the communication substrate 23. The nozzle plate 22 has a plurality of nozzles 27 arranged in parallel at a predetermined pitch to form a nozzle row. In the present embodiment, two nozzle rows are formed on the nozzle plate 22. The nozzle plate 22 is made of a silicon substrate. Then, a cylindrical nozzle 27 is formed by performing dry etching on the substrate. The compliance sheet 25 is a flexible member that is joined to the lower surface of the communication substrate 23 so as to close the opening of the common liquid chamber 32. The compliance sheet 25 has a function of absorbing a pressure change of the ink in the common liquid chamber 32.

  4 and 5 are diagrams illustrating the configuration of the communication board 23. FIG. 4 is a cross-sectional view of a main part near the individual communication port 42, and FIG. 5 is a plan view of the lower surface side of the communication board 23. The communication substrate 23 is a plate material made of a silicon substrate having a front surface (upper surface and lower surface) having a (110) plane. In the communication substrate 23, a space serving as the nozzle communication passage 36 and the common liquid chamber 32 is formed by anisotropic etching. A plurality of nozzle communication passages 36 are formed corresponding to the pressure chambers 31 along the direction in which the pressure chambers are arranged (nozzle row direction). In a state where the communication substrate 23 and the pressure chamber forming substrate 29 are joined in a positioning state, each nozzle communication passage 36 communicates with one end of the corresponding pressure chamber 31 in the longitudinal direction. The common liquid chamber 32 is a long space along the nozzle row direction (in other words, the direction in which the pressure chambers 31 are juxtaposed). The common liquid chamber 32 includes a first liquid chamber 51 that penetrates through the communication substrate 23 in the thickness direction, and a direction from the lower surface (the first surface in the present invention) to the upper surface (the second surface in the present invention) of the communication substrate 23. And a second liquid chamber 52 formed by etching so as to be halfway in the thickness direction of the communication substrate 23 and leaving the ceiling 40 on the upper surface side as described later.

  The opening of the first liquid chamber 51 on the upper surface side of the communication substrate 23 communicates with the ink introduction space 46 formed in the case 26. Then, the ink flows from the ink introduction path 45 and the ink introduction space 46 into the first liquid chamber 51. The second liquid chamber 52 (corresponding to a passage empty space in the present invention) is a depression communicating with the first liquid chamber 51. One end of the second liquid chamber 52 in the longitudinal direction of the pressure chamber (the end on the side remote from the nozzle 27) communicates with the first liquid chamber 51, while the other end in the same direction (the end on the individual channel side in the present invention). Is formed at a position corresponding to the lower side of the pressure chamber 31. At the other end of the second liquid chamber 52, the lower surface of the ceiling portion 40, that is, the ceiling surface of the second liquid chamber 52 (corresponding to the bottom surface on the second surface side in the present invention) is directed toward the lower surface of the communication substrate 23. An inclined surface 41 is formed. An individual communication port 42 is formed so as to penetrate the communication board 23 from the middle of the inclined surface 41. The plurality of individual communication ports 42 are formed in the nozzle row direction corresponding to the respective pressure chambers 31 of the pressure chamber forming substrate 29. One end (lower end) of the individual communication port 42 opens in the middle of the inclined surface 41 and communicates with the second liquid chamber 52, and the other end (upper end) of the individual communication port 42 opens on the upper surface of the communication substrate 23. As a result, the pressure chamber 31 of the pressure chamber forming substrate 29 is individually communicated.

By adopting such a configuration, when the thickness of the communication substrate 23 is T, the length of the individual communication port 42 is L, and the substantial depth of the second liquid chamber 52 is D,
L + D> T
It can be. Here, the “substantial depth of the second liquid chamber 52” refers to the depth of the main part of the second liquid chamber 52 excluding the part where the inclined surface 41 is formed. 23 means the depth from the lower surface of the second liquid chamber 52 to the ceiling surface of the second liquid chamber 52 (the lower surface of the ceiling portion 40). Here, the ceiling surface of the second liquid chamber 52 is a plane parallel to the (110) plane, and is the most eroded portion of the second liquid chamber 52 by etching. Therefore, it can be said that the substantial depth is the depth of the deepest part of the second liquid chamber 52.

As a result, the required depth D of the second liquid chamber 52 of the common liquid chamber 32 and the required length L of the individual communication port 42, which are in a trade-off relationship in the conventional configuration, are secured. Can be compatible. That is, by adjusting the opening position of the individual communication port 42 on the inclined surface 41 without being influenced by the depth D of the second liquid chamber 52, the length L of the individual communication port 42 is arbitrarily set, that is, the necessary length is set. L can be set. Therefore, the flow path resistance and the inertance of the individual communication port 42 can be appropriately adjusted. Here, assuming that the sectional (opening) radius of the individual communication port 42 is r, the viscosity of the ink is μ, and the density of the ink is ρ, the flow path resistance R and the inertance M are derived by the following approximate expressions.
R = 8 μL / πr ⁴
M = ρL / πr ²
Since the size of the cross section of the individual communication port 42 is determined to some extent by the processing method, the balance between the flow resistance and the inertance in the individual communication port 42 is adjusted by appropriately setting the length L of the individual communication port 42. can do.
On the other hand, as for the second liquid chamber 52, the required depth D can be secured without being affected by the length L of the individual communication port 42, so that pressure loss can be suppressed. By adopting such a configuration, even if the thickness T of the communication substrate 23 tends to be smaller, the required length L of the individual communication port 42 and the necessary second liquid chamber 52 are required. Since the depth D can be ensured at the same time, it is possible to cope with the downsizing of the recording head 3 without lowering the ink ejection efficiency or the like (that is, without affecting the ejection characteristics).
Regarding the formation position of the individual communication port 42, the relationship between the distance d from the end of the second liquid chamber 52 on the individual communication port 42 side to the center axis of the individual communication port 42 and the depth D of the second liquid chamber 52. (See FIG. 4), the following equation d ≦ 1.73D
It is desirable to satisfy Thereby, the formation position of the individual communication port 42 can be appropriately determined based on the required depth D of the second liquid chamber 52.

  In the second liquid chamber 52, an inclined surface 41 is provided at an end opposite to the first liquid chamber 51 side to form a wedge-shaped space, and one end of the individual communication port 42 is opened during the inclination of the inclined surface 41. With this configuration, the cross-sectional area of the flow path of the second liquid chamber 52 becomes gradually narrower from the first liquid chamber 51 side toward each individual communication port 42 on the inclined surface 41. Thereby, the flow velocity of the ink flowing from the first liquid chamber 51 side (ink supply side) toward the individual communication port 42 is increased. This makes it possible to improve the discharge property of bubbles in the second liquid chamber 52.

  Further, by forming the inclined surface 41, the acute angle portion (refer to the symbol p in FIGS. 4 and 6) of the opening on the individual communication port 42 side in the second liquid chamber 52 is inclined to the inclined end (the inclined lower end in FIG. 4). By forming the inclined surface 41, there is no sharp groove-like path (a portion where the inner walls defining the second liquid chamber 52 intersect at an acute angle) at the corner of the second liquid chamber 52. Thus, even if the adhesive leaks from the joint between the communication substrate 23 and the compliance sheet 25, capillary force is unlikely to be generated, so that the adhesive can be prevented from climbing up. This prevents problems such as the individual adhesive blocking the individual communication port 42.

  Next, a process of forming the second liquid chamber 52 and the individual communication port 42 in the communication substrate 23 will be described with reference to FIGS. In each of the drawings, (a) is a plan view near the position where the individual communication port 42 is formed in the communication board 23, (b) is a cross-sectional view taken along the line AA in (a), and (c) is B in (a). The sectional view taken along the line B is shown.

  First, as shown in FIG. 6B, one surface of the silicon wafer which is the base material 23 'of the communication substrate 23 (the surface to be joined to the pressure chamber forming substrate 29, the second surface in the present invention) ), A pilot hole 42 ′ to be the individual communication port 42 is formed at a location where the individual communication port 42 is to be formed (first step). The pilot hole 42 'is formed halfway in the thickness direction of the base material 23' by, for example, an etching method such as the Bosch method. That is, the pilot hole 42 'is formed by sequentially repeating the plasma etching step and the protective film forming step of the inner peripheral wall of the hole. The depth of the pilot hole 42 ′ is adjusted to be slightly deeper than the length L required for the individual communication port 42. The method of forming the pilot hole 42 'is not limited to the illustrated one, and various methods such as a method using a laser can be adopted. However, the depth of the pilot hole 42' can be arbitrarily adjusted. Is desirable.

  Next, a silicon oxide film (hereinafter, referred to as a first surface in the present invention) on the other surface of the base material 23 ′ (the surface on the side to be joined to the nozzle plate 22 and the compliance sheet 25) by a thermal oxidation treatment or the like. , Simply referred to as an oxide film). It should be noted that not only a silicon oxide film but also a nitride film or the like may be used as long as it functions as a resist to an etching solution during etching. Thereafter, as shown in FIG. 6, a resist pattern 55 is provided on the oxide film through exposure through a mask and development (second step). Here, in the resist pattern 55, the (110) plane, which is the surface of the base material 23 ', and the first (111) plane, which is orthogonal to the nozzle row direction (vertical direction in FIG. 6 (a)). A pair of first partition patterns 56a and 56b and a second (111) plane perpendicular to the (110) plane, which is the surface of the base material 23 ', and inclined with respect to the first (111) plane. With the second partition pattern 57, a resist pattern 55 that surrounds the planned formation position of the inclined surface 41 (hereinafter, referred to as the planned inclined surface formation position) 41 'from three directions is formed for each of the planned formation positions of the individual communication port 42. .

  After the formation of the resist pattern 55, the surface ((110) plane) of the base material 23 'on which the resist pattern 55 is formed is etched using, for example, an etching solution composed of an aqueous solution of potassium hydroxide (KOH). Is performed (third step). At this time, since the etching rate of the (111) plane is lower than the etching rate of the (110) plane, the (110) plane is mainly etched as shown in FIG. In the figure, the plane parallel to the (110) plane is the part that becomes the ceiling surface of the second liquid chamber 52 as described above. Here, in addition to the first (111) plane and the second (111) plane, the silicon substrate as the base material 23 ′ is inclined at about 30 ° with respect to (110) and has the first (111) plane. It has a third (111) plane inclined at about 50 ° with respect to the (111) plane. For this reason, as shown in FIG. 7, as the etching proceeds, the third (111) is formed at the inclined surface formation expected position 41 ′ surrounded by the first partition patterns 56 a and 56 b and the second partition pattern 57. ) Surface appears. In addition, a partition wall 58 having a side surface composed of the first (111) surface appears between adjacent inclined surface formation positions 41 ′. A resist pattern 55 is formed on an upper portion of the partition wall 58. The resist pattern 55 is formed from an end face on the first liquid chamber 51 side (the right end face in FIG. 7B) to a root side (the second partition pattern 57 side). The side etch progresses toward.

  As the etching proceeds further, as shown in FIGS. 8 and 9, as the second liquid chamber 52 becomes deeper, the inclined surface 41 as the third (111) surface is compared with the (110) surface while maintaining the angle. And the skirt gradually spreads toward the first liquid chamber 51 side (right side in the figure). For this reason, the upper end of the pilot hole 42 'and the inclined surface 41 gradually approach. Further, when the side etching of the partition wall 58 advances and reaches the root portion, that is, the portion corresponding to the second partition pattern 57, the partition wall 58 disappears. Thereafter, the lower wall portion of the second partition pattern 57 is also eroded (side-etched). Then, when the etching proceeds to some extent, as shown in FIG. 10, one end of the pilot hole 42 'is opened in the middle of the inclined surface 41, and the individual communication port 42 is formed. After the pilot hole 42 ′ (individual communication port 42) is opened on the inclined surface 41, as the etching proceeds, the peripheral edge of the opening is cut and spreads in a substantially funnel shape. When such a state is reached, the etching process is terminated. After that, the excess resist pattern 55 is removed by hydrofluoric acid or the like, and the individual communication substrates 23 are formed.

  As described above, the silicon substrate that is the base material 23 ′ of the communication substrate 23 is a substrate having a surface with the (110) plane, and the inclined surface 41 is inclined with respect to the (110) plane. The inclined surface 41 can be formed at the same time when the channel space such as the second liquid chamber 52 is formed by anisotropic etching. Therefore, it is not necessary to separately increase the step of forming the inclined surface 41.

  In the above-described embodiment, the configuration in which the opening of the common liquid chamber 32 is closed by the compliance sheet 25 on the lower surface of the communication substrate 23 is exemplified. However, the present invention is not limited thereto. A configuration that is closed by the plate 22 may be adopted.

  In the above description, the communication substrate 23 in the recording head 3 has been described as an example of the flow path component of the present invention. However, the present invention relates to a method in which the silicon substrate is moved from the first surface to the opposite second surface side. Other liquid discharge heads having a flow path space formed by being depressed halfway in the thickness direction and a flow path component having an individual flow path penetrating the silicon substrate from the flow path space to the second surface side are also used. Can be applied. For example, a color material discharge head used for manufacturing a color filter such as a liquid crystal display, an electrode material discharge head used for forming an electrode such as an organic EL (Electro Luminescence) display, an FED (surface emitting display), a biochip (a biochemical element) The present invention can also be applied to a biological organic matter ejection head used in the production of the above-mentioned method.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Recording head, 14 ... Pressure generating unit, 16 ... Recording head, 21 ... Flow path unit, 22 ... Nozzle plate, 23 ... Communication board, 27 ... Nozzle, 29 ... Pressure chamber forming board, 31 ... Pressure Chamber, 32: common liquid chamber, 35: piezoelectric element, 40: ceiling, 41: inclined surface, 42: individual communication port, 51: first liquid chamber, 52: second liquid chamber, 55: resist, 56: first 1 section pattern, 57 ... second section pattern, 58 ... partition wall

Claims (4)

A flow path component that is joined to a member in which a plurality of pressure chambers respectively communicating with a plurality of nozzles are formed,
A flow path void formed to be depressed halfway in the thickness direction from the first surface of the silicon substrate toward the opposite second surface, and provided in common to the plurality of pressure chambers;
Having an individual flow path that is individually provided for each of the pressure chambers, penetrating the silicon substrate from the flow path space to the second surface side,
The flow path void has a bottom surface extending parallel to the second surface, and an inclined surface inclined from the bottom surface toward the first surface,
One end of the individual flow path opens on the inclined surface,
The sum of the length L of the individual flow channel and the depth D from the first surface to the bottom surface of the flow channel space in the thickness direction of the silicon substrate is larger than the thickness T of the silicon substrate,
The relationship between the distance d from the end of the individual channel side in the channel empty portion to the central axis of the individual channel and the depth D from the first surface to the bottom surface of the channel empty portion is as follows: Formula d ≦ 1.73D
A flow path component characterized by satisfying the following. The silicon substrate is a substrate having the first surface and the second surface as (110) surfaces,
The flow path component according to claim 1, wherein the inclined surface is a (111) surface inclined with respect to the (110) surface. A flow path component according to claim 1 or 2,
A pressure chamber forming member in which a pressure chamber communicating with the nozzle is formed,
With
The individual flow path communicates with the pressure chamber,
A liquid ejection head, wherein the liquid from the flow passage space is supplied to the pressure chamber through the individual flow passage.   A liquid discharge apparatus comprising the liquid discharge head according to claim 3.

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