The present application is based on, and claims priority from JP Application Serial Number 2018-159202, filed Aug. 28, 2018, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus.
A known liquid ejecting head that ejects a liquid from nozzles by increasing pressures inside pressure chambers, in which the liquid is filled, with piezoelectric elements has been proposed. Each of the plurality of piezoelectric elements are electrically coupled to a wiring substrate through wires that are connected to the piezoelectric elements. JP-A-2014-188782 discloses a configuration in which the wiring substrate and the wires are reliably coupled to each other by forming an unevenness in a surface of each wire. For example, a nonconductive adhesive agent (non-conductive paste or NCP) is used to bond the wiring substrate.
In a technique in JP-A-2014-188782, protrusions formed on the surface of each of the plurality of wires are arranged in a direction intersecting the wires. With such a configuration, the flow of the adhesive agent bonding the wiring substrate becomes obstructed easily with the protrusions. Accordingly, there is a problem in that excessive load is needed in mounting the wiring substrate.
In order to overcome the above issue, a liquid ejecting head according to a suitable aspect of the present disclosure includes a first piezoelectric element that ejects a liquid inside a first pressure chamber from a nozzle, a second piezoelectric element that ejects a liquid inside a second pressure chamber from a nozzle, a first wire that extends in a first direction and that electrically couples the first piezoelectric element and a wiring substrate to each other, and a second wire that is adjacent to the first wire in a second direction intersecting the first direction and that extends in the first direction, the second wire electrically coupling the second piezoelectric element and the wiring substrate to each other. The first protrusion is formed on a surface of the first wire in a mounting area to where the wiring substrate is joined, and a second protrusion is formed on a surface of the second wire in the mounting area and at a position different from that of the first protrusion in the first direction.
As illustrated as an example in
The moving mechanism 24 reciprocates the liquid ejecting head 26 in an X direction under the control of the control unit 20. The X direction is a direction orthogonal to the Y direction in which the medium 12 is transported. The moving mechanism 24 of the first embodiment includes a substantially box-shaped transport body 242 that houses the liquid ejecting head 26 and a transport belt 244 to which the transport body 242 is fixed. Note that a configuration in which a plurality of liquid ejecting heads 26 are mounted in the transport body 242 or a configuration in which the liquid container 14 is mounted in the transport body 242 together with the liquid ejecting head 26 can be adopted.
The liquid ejecting head 26 ejects ink, which is supplied from the liquid container 14, to the medium 12 through a plurality of nozzles (in other words, ejection holes) under the control of the control unit 20. Concurrently with the transportation of the medium 12 performed with the transport mechanism 22 and the repetitive reciprocation of the transport body 242, the liquid ejecting head 26 ejects ink onto the medium 12 to form a desired image on a surface of the medium 12. Note that a direction perpendicular to an XY plane is hereinafter referred to as a Z direction. The direction in which the ink is ejected by the liquid ejecting head 26 corresponds to the Z direction. The XY plane is, for example, a plane parallel to the surface of the medium 12.
As illustrated as an example in
The nozzle plate 41 is a plate-shaped member having the plurality of nozzles N formed therein. Each of the plurality of nozzles N is a circular through hole through which ink is ejected. The nozzle plate 41 is manufactured by processing a single crystal substrate formed of silicon (Si) using a semiconductor manufacturing technique such as, for example, photolithography and etching. However, any known materials and any known manufacturing methods can be adopted to manufacture the nozzle plate 41.
As illustrated in
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The housing 36 is a case that stores the ink supplied to the plurality of pressure chambers C and is, for example, formed of a resin material by injection molding. Spaces Rb, supply holes 361, and an insertion hole 362 are formed in the housing 36. The insertion hole 362 is a through hole elongated in the Y direction. The supply holes 361 are pipe lines through which the ink is supplied from the liquid container 14 and are in communication with the spaces Rb. The spaces Rb of the housing 36 and the spaces Ra of the flow path substrate 31 are in communication with each other. The spaces configured by the space Ra and the space Rb function as liquid storage chambers R that store the ink supplied to the plurality of pressure chambers C.
The ink that has been supplied from the liquid container 14 and that has passed through the supply holes 361 is stored in the liquid storage chambers R. The ink that has been stored in the liquid storage chambers R is branched from the relay liquid chambers 316 to the supply flow paths 312 and is supplied and filled in parallel into the plurality of pressure chambers C. The vibration absorber 42 is a flexible film constituting wall surfaces of the liquid storage chambers R and absorbs the pressure fluctuations of the ink inside the liquid storage chambers R.
As illustrated as an example in
A conductive layer 344 and a conductive layer 345 spaced apart from each other are formed on a surface of the second electrode 343. The conductive layer 344 and the conductive layer 345 are strip-like electrodes extending in the Y direction across the plurality of piezoelectric elements 34. The conductive layer 344 and the conductive layer 345 are formed of metal having a low resistance such as, for example, gold (Au), and functions as an auxiliary wire that suppresses the voltage in the second electrode 343 from dropping.
As illustrated in
An accommodation portion 351 corresponding to the first line La and an accommodation portion 352 corresponding to the second line Lb are formed in the protective plate 35. The accommodation portion 351 and the accommodation portion 352 are cavities long in the Y direction formed in a surface, among the surfaces of the protective plate 35, opposing the flow path structure 30. The plurality of piezoelectric elements 34a are accommodated in the accommodation portion 351, and the plurality of piezoelectric elements 34b are accommodated in the accommodation portion 352. The protective plate 35 exerts a function of preventing moisture or external air from adhering to the piezoelectric elements 34 and a function of reinforcing the mechanical strength of the flow path structure 30. An insertion hole 353 elongated in the X direction is formed in the protective plate 35 of the first embodiment. The insertion hole 353 is a through hole formed between the accommodation portion
351 and the accommodation portion 352.
The wiring substrate 51 is a mounted component that electrically couples the liquid ejecting head 26 and the control unit 20 to each other. A flexible connecting component such as, for example, a flexible printed circuit (FPC) or a flexible flat cable (FFC) is, desirably, used as the wiring substrate 51. As illustrated as an example in
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The portion of the wiring substrate 51 joined to the mounting area Q is also illustrated in
Note that in a configuration in which the surfaces of the wires 60 are simple flat surfaces throughout the entire surfaces, due to the surface roughness, for example, the surfaces of the wires 60 and the surfaces of the wires 54 of the wiring substrate 51 may not be sufficiently adhered to each other. When a conductive adhesive agent is used in mounting the wiring substrate 51, sufficient adhesion between the surfaces of the wires 60 and the surfaces of the wires 54 is not required; however, when a nonconductive adhesive agent is used, sufficient electric connections between the wires 60 and the wires 54 may not be obtained if the wires 60 and the wires 54 are not sufficiently adhered to each other. Since the plurality of protrusions 61 are formed on the wires 60 in the first embodiment, the nonconductive adhesive agent is situated not only between each space between two wires 60 adjacent to each other in the Y direction but also in each space between two protrusions 61 adjacent to each other in the X direction. According to the above configuration, since the surfaces of the protrusions 61 sufficiently adhere to the surfaces of the wires 54 of the wiring substrate 51, electric connections between the wires 60 and the wires 54 are obtained sufficiently. Accordingly, even when a nonconductive adhesive agent is used to mount the wiring substrate 51, connection failure between the wires 60 and the wiring substrate 51 can be suppressed. In the first embodiment in particular, since the plurality of protrusions 61 are formed on each of the wires 60, compared with a configuration in which a single protrusion 61 alone is formed on each wire 60, the effect of suppressing the connection failure between the wires 60 and the wiring substrate 51 is markedly noticeable.
As illustrated as an example in
When viewed in plan view in the Z direction, the base portions 64 are island-shaped portions formed so as to overlap the underlayer portions 63. The base portions 64 of the first embodiment are each formed so as to have an elongated shape extending in the Y direction. The base portion 64 is an insulating layer formed of a layer that is the same as that of the piezoelectric layer 342 of the piezoelectric elements 34. In other words, by selectively removing a dielectric film having a predetermined film thickness, the piezoelectric layer 342 and the base portions 64 are formed integrally. As described above, by forming the base portions 64 so as to overlap the underlayer portions 63, the base portions 64 adhere to the surface of the underlayer portions 63; accordingly, the possibility of the base portions 64 peeling off can be reduced.
By forming the wires 60 so as to overlap the base portions 64, the protrusions 61 reflecting the shapes of the base portions 64 are formed on the surfaces of the wires 60. In other words, the protrusions 61 of the wires 60 are portions positioned above the surfaces of the base portions 64 in the wires 60. As illustrated in
As illustrated as an example in
As illustrated as an example in
The positions of the protrusion 61a in the X direction are between two protrusions 61b on the corresponding wire 60b adjacent to each other in the X direction. For example, the positions of the protrusions 61a in the X direction are where midpoints of two adjacent protrusions 61b on the corresponding wire 60b are positioned. Similarly, the positions of the protrusions 61b in the X direction are between two protrusions 61a on the corresponding wire 60a adjacent to each other in the X direction and are, for example, where midpoints of two adjacent protrusions 61a are positioned. As understood from the description above, in the first embodiment, the plurality of protrusions 61 of the wires 60 are disposed in a zigzag manner or in a staggered manner.
As described above, in the first embodiment, the positions of the protrusions 61 of two wires 60 adjacent to each other in the Y direction are different in the X direction. Accordingly, compared with a configuration (hereinafter, referred to as a “comparative example”) in which the positions of the protrusions 61 in the X direction of two wires 60 adjacent to each other in the Y direction are the same, large spaces between the protrusions 61a and the protrusions 61b are obtained. According to the above configuration, the adhesive agent 67 that bonds the wiring substrate 51 to the mounting area Q can flow more easily compared with the comparative example. Accordingly, there is an advantage in that the load needed to mount the wiring substrate 51 is reduced.
Furthermore, in a configuration in which the base portions 64 of two wires 60 adjacent to each other in the Y direction are continuous in the Y direction, the conductive material constituting the wire 60 or moisture close by is diffused along the base portions 64. Accordingly, there is a possibility of short circuiting ultimately occurring between the two wires 60 adjacent to each other in the Y direction. The first embodiment also has an advantage in that, since the base portions 64 in the two wires 60 adjacent to each other in the Y direction are separated from each other, short circuiting of the two wires 60 owing to the base portions 64 can be suppressed effectively.
Furthermore, in the first embodiment, since the wires 60 are formed on the surfaces of the base portions 64, the protrusions 61 reflecting the shapes of the base portions 64 are formed in the wires 60. Accordingly, there is an advantage in that the formation of the protrusions 61 in the wires 60 is facilitated.
A description of a second embodiment will be given. Note that in the following examples, elements having functions similar to those of the first embodiment will be denoted by applying the reference numerals used in the description of the first embodiment, and detailed description of the elements will be omitted appropriately.
When attention is given to the wire 60a and the wire 60b adjacent to each other in the Y direction, the first portions P1 of the wire 60a and the base portions 64 of the wire 60b are adjacent to each other, and the first portions P1 of the wire 60b and the base portions 64 of the wire 60a are adjacent to each other. In other words, the first portions P1 of the wire 60a are positioned between the base portions 64 of the wire 60b adjacent to the above wire 60a on one side and the base portions 64 of the wire 60b adjacent to the above wire 60a on the other side. Similarly, the first portions P1 of the wire 60b are positioned between the base portions 64 of the wire 60a adjacent to the above wire 60b on one side and the base portions 64 of the wire 60a adjacent to the above wire 60b on the other side. The second portions P2 of each wire 60 are portions other than the first portions P1 in each wire 60. A dimension of each first portion P1 in the X direction is smaller than a dimension of each second portion P2 in the X direction. Furthermore, the dimension of each first portion P1 in the X direction is larger than a dimension of each base portion 64 in the X direction.
As illustrated as an example in
An effect similar to the first embodiment can be provided in the second embodiment as well. Furthermore, since the widths W1 of the first portions P1 in the wires 60 are smaller than the widths W2 of the second portions P2, the second embodiment has an advantage in that, compared with the first embodiment, the intervals between the wires 60 can be reduced while separating each wire 60 and the base portions 64 of the other wires 60 adjacent to the wire 60 from each other. By having the widths W1 of the first portions P1 be smaller than the width W2 of the second portions P2, the wires 60 and the base portions 64 are separated from each other; accordingly, the effect described above in that short circuiting of two wires 60 adjacent to each other can be suppressed is markedly noticeable.
Note that in
In the first embodiment, a configuration in which the positions of the protrusions 61a of the wires 60a and the positions of the protrusions 61b of the wires 60b are different in the X direction has been described as an example. In the third embodiment, the positions of the protrusions 61a of the wires 60a, the positions of the protrusions 61b of the wires 60b, and the positions of the protrusions 61c of the wires 60c are different in the X direction. In other words, while in the second embodiment, the protrusions 61a of the wires 60a and the protrusions 61b of the wires 60b are two rows arranged in a zigzag manner, in the third embodiment, the protrusions 61a of the wires 60a, the protrusions 61b of the wires 60b, and the protrusions 61c of the wires 60c are three rows arranged in a zigzag manner.
An effect similar to that of the first embodiment can be provided in the third embodiment as well. Note that while in
The various embodiments described above as examples can be modified in various ways. Specific modification modes that can be applied to the embodiments described above will be described below as examples. Two or more optionally selected modes from the examples below can be merged as appropriate as long as they do not contradict each other.
(1) While in the embodiments described above, the plurality of protrusions 61 are formed on the surfaces of the wires 60 at equal intervals, the interval between two protrusions 61 adjacent to each other in the X direction is optional. In other words, the configuration in which the plurality of protrusions 61 of the wires 60 are arranged at equal intervals is not essential.
(2) While in the embodiments described above, the first electrodes 341 of the piezoelectric elements 34 are individual electrodes and the second electrodes 343 are common electrodes, the first electrodes 341 may be common electrodes and the second electrodes 343 may be individual electrodes. In the configuration in which the second electrodes 343 are individual electrodes, the wires 60 are electrically coupled to the second electrodes 343 of the piezoelectric elements 34. Alternatively, both the first electrodes 341 and the second electrodes 343 may be individual electrodes.
(3) While in the embodiments described above, the plurality of wires 60 are formed in the mounting area Q between the plurality of piezoelectric elements 34a and the plurality of piezoelectric elements 34b, the plurality of piezoelectric elements 34 may be formed only in an area on one side of the mounting area Q in the X direction. In other words, the configuration in which the plurality of wires 60 are alternatively drawn out to the positive side and the negative side in the X direction is omitted.
(4) While in the embodiments described above, the wires 60, the underlayer portions 63, and the base portions 64 are formed from a layer that is the same as that constituting the piezoelectric elements 34, the wires 60, the underlayer portions 63, and the base portions 64 may be formed at a process different from the process of manufacturing the piezoelectric elements 34.
(5) While in the embodiments described above, the protrusions 61 are formed on the surfaces of the wires 60 by forming the wires 60 on the surface of the flow path structure 30 on which the base portions 64 are formed, the method or the configuration of forming the protrusions 61 is not limited to the examples described above. For example, a specific portion of a conductive film formed with a predetermined film thickness may be removed in the film thickness direction and portions other than the above portion may be formed as the protrusions 61. As understood from the above description, the underlayer portions 63 and the base portions 64 can be omitted.
(6) While in the embodiments described above, the serial type liquid ejecting apparatus 100 in which the transport body 242 in which the liquid ejecting head 26 is mounted is reciprocated has been described as an example, a line type liquid ejecting apparatus in which a plurality of nozzles N are distributed across the entire width of the medium 12 can also be applied to the present disclosure.
(7) The liquid ejecting apparatus 100 described as an example in the embodiments described above may be employed in various apparatuses other than an apparatus dedicated to printing, such as a facsimile machine and a copier. Note that the application of the liquid ejecting apparatus of the present disclosure is not limited to printing. For example, a liquid ejecting apparatus that ejects a coloring material solution is used as a manufacturing apparatus that forms a color filter of a display device such as a liquid crystal display panel. Furthermore, a liquid ejecting apparatus that ejects a conductive material solution is used as a manufacturing apparatus that forms wiring and electrodes of a wiring substrate. Furthermore, a liquid ejecting apparatus that ejects a solution of an organic matter related to a living body is used, for example, as a manufacturing apparatus that manufactures a biochip.
Number | Date | Country | Kind |
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2018-159202 | Aug 2018 | JP | national |