The entire disclosure of Japanese Patent Application No. 2017-244255, filed Dec. 20, 2017 is expressly incorporated by reference herein.
The present invention relates to techniques for ejecting liquid, such as ink or the like.
Heretofore, liquid ejecting heads each configured to eject liquid, such as ink or the like, through a plurality of nozzles have been proposed. For example, in JP-A-2017-124540, there is disclosed a liquid ejecting head including a flow path formation substrate in which pressure generation chambers are formed; piezoelectric elements each configured to cause pressure inside a corresponding one of the pressure generation chambers to vary; and a driving circuit configured to supply driving signals to the respective piezoelectric elements. Further, a driving circuit substrate is disposed between the flow path formation substrate and the driving circuit. Moreover, wirings for transmitting, to the driving circuit, signals and power sources supplied from external circuits, and wirings for transmitting the driving signals, which are output from the driving circuit, to the respective piezoelectric elements are formed on the driving circuit substrate.
Under the techniques disclosed in JP-A-2017-124540, however, it is actually difficult to sufficiently lower the resistances of the wirings formed on the driving circuit substrate, and there is a room for further improvement from a viewpoint of the minimization of heat generation and waveform blunting of the driving signals due to the resistances of the wirings.
An advantage of some aspects of the invention is that techniques that enable the realization of further lowering the resistances of wirings formed on a wiring substrate constituting a liquid ejecting head are provided.
In configuration 1, namely, a preferable configuration of a liquid ejecting head according to an aspect of the invention, the liquid ejecting head includes a flow path formation portion in which a plurality of pressure chambers each communicating with a corresponding one of a plurality of nozzles are formed; a plurality of driving elements each configured to cause liquid inside a corresponding one of the pressure chambers to be ejected through a corresponding one of the nozzles; a driving circuit configured to output a driving pulse for driving each of the driving elements to the each of the driving elements; and a wiring substrate including a base body portion disposed between the flow path formation portion and the driving circuit, and a signal wiring formed on the base body portion and configured to transmit a driving signal for use in generation of the driving pulse by the driving circuit to the driving circuit from an input terminal. Further, the signal wiring includes a first portion overlapping, in a plan view, at least one coupling terminal included in the driving circuit and coupled to the signal wiring, and a second portion located on the side of the input terminal when seen from the first portion, and the total number of wirings constituting the second portion is larger than the total number of wirings constituting the first portion. In the above configuration, the total number of wirings constituting the second portion included in the signal wiring for use in transmission of the driving signal and located on the side of the input terminal is larger than the total number of wirings constituting the first portion included in the signal wiring and overlapping, in a plan view, the at least coupling terminal included in the driving circuit, and thus, the wiring resistance of the second portion is greatly reduced, as compared with a configuration in which the total number of wirings constituting the second portion is equal to the total number of wirings constituting the first portion. Accordingly, in the signal wiring, heat generation and waveform blunting of the driving signal are reduced.
In configuration 2, namely, a preferable example of configuration 1, a plurality of relay wirings each electrically interconnecting the driving circuit and a corresponding one of the driving elements may be formed on a face on the side of the driving circuit among external faces of the base body portion, and at least one portion of a coupling region which is included in the base body portion and within which the relay wirings are formed may be located in a first direction in which the signal wiring extends when seen from the second portion and in a second direction intersecting with the first direction when seen from the first portion. The above configuration allows the signal wiring and the relay wirings to be formed utilizing the surface of the base body portion in an efficient manner, and thus brings about an advantage in which the downsizing of the base body portion is achieved.
In configuration 3, namely, a preferable example of configuration 1 or configuration 2, each of the relay wirings may be electrically coupled to a corresponding one of the driving elements via a first penetration wiring inside a corresponding one of penetration holes formed in the base body portion. In the above configuration, each of the relay wirings is electrically coupled to a corresponding one of the driving elements via the first penetration wiring inside a corresponding one of the penetration holes of the base body portion, and thus, the above configuration brings about an advantage in which the configuration of the liquid ejecting head is greatly simplified, as compared with a configuration in which the relay wirings are electrically coupled to the respective driving elements via, for example, a flexible wiring substrate.
In configuration 4, namely, a preferable example of any one of configurations 1 to 3, the signal wiring may include a first wiring portion formed on a first face on the side of the driving circuit among external faces of the base body portion, and a second wiring portion formed on a second face on the side opposite the first face among the external faces of the base body portion. Further, the first wiring portion and the second wiring portion may be electrically coupled to each other via at least one second penetration wiring inside at least one penetration hole formed in the base body portion, and in the second portion, the second wiring portion may include a plurality of wirings. In the above configuration, the signal wiring is constituted by the first wiring portion formed on the first face of the base body portion and the second wiring portion formed on the second face of the base body portion, and thus, the above configuration brings about an advantage in which a size of the base body portion, which is required to be sufficient to form the signal wiring, is greatly reduced, and concurrently therewith, the wiring resistance of the signal wiring is greatly reduced, as compared with a configuration in which the signal wiring is formed on only a single surface of the base body portion.
In configuration 5, namely, a preferable example of configuration 4, at least one coupling terminal included in the driving circuit and coupled to the first wiring portion does not overlap the at least one second penetration wiring in a plan view. In a configuration in which the at least one coupling terminal of the driving circuit overlaps the at least one second penetration wiring in a plan view, a wiring failure, such as wiring breaking, wiring damage, or the like, is likely to occur in the at least one second penetration wiring due to pressure applied to the base body portion from the at least one coupling terminal. With the above-described configuration, in which the at least one coupling terminal of the driving circuit does not overlap the at least one second penetration wiring in a plan view, even in the case where pressure is applied to the base body portion from the at least one coupling terminal, a failure of the at least one second penetration wiring due to the relevant pressure is reduced.
In configuration 6, namely, a preferable example of any one of configurations 1 to 5, the base body portion may be a long plate-shaped member, and the first portion may extend along a long side of the base body portion. In the above configuration, the first portion of the signal wiring extends along a long side of the base body portion, and thus, the above configuration brings about an advantage in which, for example, in a configuration in which a long-shaped driving circuit extending along the base body portion is disposed in the base body portion, the driving signal can be supplied over the whole of the long direction of the driving circuit from the signal wiring.
In configuration 7, namely, a preferable example of any one of configurations 1 to 6, the liquid ejecting head may further include a power supply wiring formed on the base body portion and being for use in supply of a power source voltage to the driving circuit from an input terminal. Further, the power supply wiring may include a third portion overlapping, in a plan view, at least one coupling terminal included in the driving circuit and coupled to the power supply wiring, and a fourth portion located on the side of the input terminal for the power source voltage when seen from the third portion, and the total number of wirings constituting the fourth portion may be larger than the total number of wirings constituting the third portion. In the above configuration, the total number of wirings constituting the fourth portion included in the power supply wiring for use in supply of a power source voltage to the driving circuit and located on the side of the input terminal is larger than the total number of wirings constituting the third portion included in the power supply wiring and overlapping the driving circuit, and thus, the wiring resistance of the fourth portion is greatly reduced, as compared with a configuration in which the total number of wirings constituting the fourth portion is equal to the total number of wirings constituting the third portion. Accordingly, the occurrence of problems in the power supply wiring, such as heat generation and the like, is reduced.
In configuration 8, namely, a preferable configuration of a liquid ejecting apparatus according to another aspect of the invention, the liquid ejecting apparatus includes the liquid ejecting head according to any one of configurations 1 to 7 having been exemplified above. An exemplification of a liquid ejecting apparatus is a printing apparatus that ejects ink, but the application of the liquid ejecting apparatus according to another aspect of the invention is not limited to the printing.
In configuration 9, namely, a preferable configuration of a wiring substrate according to a further aspect of the invention, the wiring substrate is used in a liquid ejecting head including a flow path formation portion in which a plurality of pressure chambers each communicated with a corresponding one of a plurality of nozzles are formed; a plurality of driving elements each configured to cause liquid inside a corresponding one of the pressure chambers to be ejected through a corresponding one of the nozzles; and a driving circuit configured to output a driving pulse for driving each of the driving elements to the each of the driving elements, and the wiring substrate includes a base body portion disposed between the flow path formation portion and the driving circuit; and a signal wiring formed on the base body portion and configured to transmit a driving signal for use in generation of the driving pulse by the driving circuit to the driving circuit from an input terminal. Further, the signal wiring includes a first portion, and a second portion located on the side of the input terminal when seen from the first portion, and the total number of wirings constituting the second portion is larger than the total number of wirings constituting the first portion. In the above configuration, the total number of wirings constituting the second portion included in the signal wiring for use in transmission of the driving signal and located on the side of the input terminal is larger than the total number of wirings constituting the first portion included in the signal wiring and overlapping, in a plan view, the at least coupling terminal included in the driving circuit, and thus, the wiring resistance of the second portion is greatly reduced, as compared with a configuration in which the total number of wirings constituting the second portion is equal to the total number of wirings constituting the first portion. Accordingly, in the signal wiring, heat generation and waveform blunting of the driving signal are reduced.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
As exemplified in
The movement mechanism 24 causes the liquid ejecting head 26 to reciprocate in an X direction under the control of the control unit 20. The X direction is a direction intersecting with (typically, orthogonally intersecting with) the Y direction, in which the medium 12 is transported. The movement mechanism 24 of the first embodiment includes a transporting unit 242 (a carriage) and a transporting belt 244. The transporting unit 242 is an approximately box-shaped unit containing the liquid ejecting head 26, and is secured to the transporting belt 244. Here, a configuration in which a plurality of the liquid ejecting heads 26 are mounted in the transporting unit 242 and a configuration in which the liquid reservoirs 14 are mounted together with the liquid ejecting head 26 in the transporting unit 242 can be also employed.
The liquid ejecting head 26 ejects the inks supplied from the respective liquid reservoirs 14 onto the medium 12 through a plurality of nozzles (ejection holes) under the control of the control unit 20. The liquid ejecting head 26 ejects the inks onto the medium 12 in parallel with the transport of the medium 12 by the transport mechanism 22 as well as the iterative reciprocations of the transporting unit 242, thereby allowing desired images to be formed on the surface of the medium 12. It should be noted that a direction perpendicular to an X-Y plane (for example, a plane parallel to the surface of the medium 12) will be referred to as a Z direction hereinafter. A direction in which the inks are ejected by the liquid ejecting head 26 (typically, this direction being the vertical direction) corresponds to the Z direction
As exemplified in
As exemplified in
As exemplified in
The nozzle plate 62 is a plate-shaped member in which the plurality of nozzles N are formed, and is disposed on the surface of a positive Z direction side of the flow path substrate 32. Each of the plurality of nozzles N is a circular shaped penetration hole that allows the ink to pass through the relevant penetration hole. Further, the plurality of nozzles N constituting the first row L1 and the plurality of nozzles N constituting the second row L2 are formed in the nozzle plate 62 of the first embodiment. The nozzle plate 62 is manufactured by processing a silicon (Si) single-crystal substrate utilizing, for example, a semiconductor manufacturing technique (a processing technique, such as dry edging or wet edging). In this regard, however, in the manufacturing of the nozzle plate 62, a known material and a known manufacturing method can be optionally employed.
As exemplified in
As exemplified in
As exemplified in
As understood from
Thus, each of the pressure chambers C communicates with a corresponding one of the nozzles N via a corresponding one of the communication flow paths 324, and further communicates with the space Ra via a corresponding one of the supply flow paths 322 and the supply liquid chamber 326.
As exemplified in
The wiring substrate 46 of
The chassis portion 48 is a case for storing therein the inks to be supplied to the plurality of pressure chambers C (and further, the plurality of nozzles N). As exemplified in
The wiring substrate 46 includes a base body portion 70 and a plurality of wirings 72. The base body portion 70 is an insulating plate-shaped member that is long in the Y direction, and is located between the flow path formation portion 30 and the driving circuit 50. The base body portion 70 is manufactured by processing a silicon single-crystal substrate utilizing, for example, a semiconductor manufacturing technique. In this regard, however, a known material and a known manufacturing method can be optionally employed in the manufacturing of the base body portion 70.
As exemplified in
The plurality of wirings 72 for transmitting the voltages (VDD, VSS, and VBS) and the signals (S and D), which are supplied from the control unit 20 via the external wiring 52, are formed on the first face F1 and the second face F2 of the base body portion 70. Specifically, as exemplified in
The power supply wiring 72a, the power supply wiring 72b, the signal wiring 72c, and the reference wiring 72e are wiring sets each constituted by stacked layers of a plurality of conductive layers (each of the wiring set being referred to as “a stacked-layer wiring” hereinafter).
As exemplified in
As exemplified in
As understood from
The reference wiring 72e illustrated in
The penetration wiring e3 is an conductive member formed inside a penetration hole penetrating through the base body portion 70, and electrically interconnects the first wiring portion e1 and the second wiring portion e2. As exemplified in
The signal wiring 72c is a wiring for supplying the driving signal D to the driving circuit 50, and is configured to include a first wiring portion c1, a second wiring portion c2, and a plurality of penetration wirings c3. The first wiring portion c1 is a stacked-layer wiring formed on the first face F1 of the base body portion 70, and the second wiring portion c2 is a stacked-layer wiring formed one the second face F2 of the base body portion 70. As illustrated in
As exemplified in
By the way, in a configuration in which a coupling terminal Tc1 of the driving circuit 50 overlaps a penetration wiring c3 in a plan view, a wiring failure, such as wiring breaking, wiring damage, or the like, is likely to occur in the penetration wiring c3 due to, for example, pressure applied from the coupling terminal Tc1 at the time of mounting the driving circuit 50. Taking into consideration the above situation, in the first embodiment, each of the plurality of coupling terminals Tc1 of the driving circuit 50 does not overlap with any one of the plurality of penetration wirings c3. This configuration brings about an advantage in which, even when pressure is applied to the base body portion 70 from the coupling terminals Tc1, the wiring failure of any one of the penetration wirings c3 due to the pressure can be eliminated.
As exemplified in
On the other hand, the second portion Q2 is a portion located on the side of the input terminal Tc0 (on the negative side of the Y direction) when seen from the first portion Q1. Specifically, a portion on the side of the input terminal Tc0 when seen from one coupling terminal Tc1 that is the closest to the input terminal Tc0 among the plurality of coupling terminals Tc1 corresponds to the second portion Q2. When focusing on the transmission direction of the driving signal D, the second portion Q2 is located on the upstream side of the transmission direction of the driving signal D, compared with the first portion Q1. When focusing on positions in the X direction, the second portion Q2 is located on the side opposite the center line O when seen from the first portion Q1.
In the first portion Q1, the total number of first wirings 81 of a stacked-layer wiring constituting each of the first wiring portion c1 and the second wiring portion c2 is one. That is, the first portion Q1 is constituted by totally two first wirings 81 including one first wiring 81 of the first wiring portion c1 and one first wiring 81 of the second wiring portion c2. On the other hand, in the second portion Q2, the total number of first wirings 81 of the first wiring portion c1 is one, just like the first portion Q1; while the second wiring portion c2 is constituted by a plurality of mutually coupled first wirings (a bundle of a plurality of first wirings 81). That is, the second portion Q2 is constituted by totally three first wirings 81 including one first wiring 81 of the first wiring portion c1 and two first wirings 81 of the second wiring portion c2. As understood from the above description, in the first embodiment, for the signal wiring 72c, the total number of first wirings 81 constituting the second portion Q2 is larger than the total number of first wirings 81 constituting the first portion Q1. The first wiring 81 of the first wiring portion c1 and the first wiring 81 of the second wiring portion c2 are formed in such a way as to have approximately the same wiring width. Accordingly, in the signal wiring 72c, the resistance of the second portion Q2 is lower than that of the first portion Q1.
As exemplified in
The power supply wiring 72a of
The signal wiring 72d of
As described above, in the first embodiment, the total number of wirings constituting the second portion Q2, which is included in the signal wiring 72c for transmitting the driving signal D and which is located on the side of the input terminal Tc0, is larger than the total number of wirings constituting the first portion Q1, which is included in the signal wiring 72c and which overlaps the coupling terminals of the driving circuit 50. That is, in the above-described configuration of the first embodiment, the wiring resistance of the second portion Q2 is greatly lowered, as compared with a configuration in which the total number of the wirings of the first portion Q1 is equal to the total number of the wirings of the second portion Q2. Thus, the above-described configuration of the first embodiment brings about an advantage in which heat generation and waveform blunting of the driving signal in the signal wiring 72c can be reduced.
A second embodiment of the invention will be described below. It should be noted that, for elements included in individual exemplifications below and having functions similar to those of the elements of the first embodiment, reference signs having been used in the description of the first embodiment will be also used, and thereby the detailed descriptions of the elements included in the individual exemplifications below will be appropriately omitted.
The power supply wiring 72a of the second embodiment is sectioned into a third portion Q3 and a fourth portion Q4 in a plan view. The third portion Q3 is a portion included in the power supply wiring 72a and overlapping the arrangement of the plurality of coupling terminals Ta1 of the driving circuit 50; while the fourth portion Q4 is a portion located on the side of the input terminal Ta0 (the negative side of the Y direction) when seen from the third portion Q3. Specifically, a portion on the side of the input terminal Ta0 when seen from one coupling terminal Ta1 that is the closest to the input terminal Ta0 among the plurality of coupling terminals Ta1 corresponds to the fourth portion Q4. When focusing on the direction of electric current corresponding to the power source voltage VDD, the fourth portion Q4 is located on the upper stream side of the electric current corresponding to the power source voltage VDD, compared with the third portion Q3.
The total number of first wirings 81 of a stacked-layer wiring constituting the third portion Q3 of the power supply wiring 72a is one; while a stacked-layer wiring constituting the fourth portion Q4 of the power supply wiring 72a is configured to include two first wirings 81. As understood from the above description, in the second embodiment, for the power supply wiring 72a, the total number of the first wirings 81 constituting the fourth portion Q4 is larger than the total number of the first wirings 81 constituting the third portion Q3. The first wiring 81 of the third portion Q3 and the first wiring 81 of the fourth portion Q4 are formed in such a way as to have approximately the same wiring width. With the above configuration, in the power supply wiring 72a, the resistance of the fourth portion Q4 is lower than that of the third portion Q3. Thus, the above-described configuration of the second embodiment brings about an advantage in which problems, such as heat generation and the like, in the power supply wiring 72a can be reduced. It should be noted that, although the power supply wiring 72a for supplying the power source voltage VDD has been focused in the above description, a configuration similar to the configuration of the power supply wiring 72a of the second embodiment can be employed in other wirings for supplying voltages other than the power source voltage VDD (for example, the lower level power source voltage VSS and the reference voltage VBS).
The individual embodiments having been exemplified above can be variously modified. Specific modification configurations that can be applied to the individual embodiments described above will be exemplified below. Two or more configurations that are optionally selected from among exemplifications below can be appropriately combined within a scope where there is no inconsistency among the relevant configurations.
(1) The total number of the first wirings 81 constituting the first portion Q1 of the signal wiring 72c and the total number of the first wirings 81 constituting the second portion Q2 of the signal wiring 72c are not limited to those of the exemplification of the first embodiment. For example, the first portion Q1 of the signal wiring 72c may be constituted by four or more first wirings 81, and the second portion Q2 thereof may be constituted by three or more first wirings 81. Similarly, the total number of the first wirings 81 constituting the third portion Q3 of the power supply wiring 72a and the total number of the first wirings 81 constituting the fourth portion Q4 of the power supply wiring 72a are not limited to those of the exemplification of the second embodiment. For example, the third portion Q3 of the power supply wiring 72a may be constituted by three or more first wirings 81, and the fourth portion Q4 thereof may be constituted by three or more second wirings 82.
(2) In the first embodiment, the signal wiring 72c is formed using the first wiring portion c1 formed on the first face F1 of the base body portion 70 and the second wiring portion c2 formed on the second face F2 of the base body portion 70, but the signal wiring 72c may be formed using only a conductive pattern formed on the first face F1 of the base body portion 70. Even when the configuration in which the signal wiring 72c is formed using only the conductive pattern of the first face F1 is employed, a configuration in which, in the signal wiring 72c, the total number of the first wirings 81 constituting the first portion Q2 is larger than the total number of the first wirings 81 constituting the second portion Q1 is preferable. Further, in the second embodiment, the power supply wiring 72a is formed using the conductive pattern formed on the first face F1 of the base body portion 70, but the power supply wiring 72a may be constituted by a conductive pattern formed on the first face F1 and a conductive pattern formed on the second face F2. Even when the configuration in which the power supply wiring 72a is formed on the first face F1 and the second face F2 is employed, a configuration in which, in the power supply wiring 72a, the total number of the first wirings 81 constituting the fourth portion Q4 is larger than the total number of the first wirings 81 constituting the third portion Q3 is preferable. As understood from the above description, when a wiring is formed on the surface of the base body portion 70, the wiring is preferable regardless of whether the relevant wiring is formed on both faces or only a single face of the base body portion 70, provided that the relevant wiring is configured such that the total number of wirings of a portion B, namely, a portion corresponding to, for example, the second portion Q2 or the fourth portion Q4 and being located on the side nearer an input terminal than a portion A, namely, a portion corresponding to, for example, the first portion Q1 or the third portion Q3, is larger than the total number of wirings of the portion A.
(3) In the individual embodiments described above, one system of driving signal D has been exemplified, but a plurality of systems of driving signal D having mutually different waveforms may be utilized.
In this case, the driving circuit 50 selectively supplies a driving pulse P included in any one of the plurality of systems of driving signal D to each of the piezoelectric elements 44. In the above configuration, for each of the plurality of systems of driving signal D, a signal wiring similar to the signal wiring 72c of the first embodiment is formed.
(4) In the individual embodiments described above, each of the wirings (the power supply wiring 72a, the power supply wiring 72b, the signal wiring 72c, and the reference wiring 72e) of the wiring substrate 46 is constituted by the stacked-layer wiring, but the each wiring is not limited to the stacked-layer wiring. For example, each of the power supply wiring 72a, the power supply wiring 72b, the signal wiring 72c, and the reference wiring 72e may be constituted by a single-layer conductive pattern.
(5) A driving element for ejecting liquid (for example, ink) inside a corresponding pressure chamber C through a corresponding nozzle N is not limited to the piezoelectric element 44 having been exemplified in the individual embodiments described above. For example, a heat generation element that is heated to cause air bubbles to be generated inside a corresponding pressure chamber C so as to cause pressure inside the corresponding pressure chamber C to vary can be utilized as the driving element. As understood from the above exemplification, the driving element is comprehensively represented as an element that causes liquid inside a corresponding pressure chamber C to be ejected through a corresponding nozzle N (typically, the relevant element being an element that applies pressure to the inside of the corresponding pressure chamber C), regardless of which of the operation schemes (namely, the scheme using piezoelectricity or the scheme using heat) is employed and regardless of what a specific configuration is.
(6) In the individual embodiments described above, the serial type liquid ejecting apparatus 100 that reciprocates the transporting unit 242 mounting the liquid ejecting head 26 has been exemplified, but the invention can be applied to a line type liquid ejecting apparatus with its plurality of nozzles N distributed across the entire width of the medium 12.
(7) The liquid ejecting apparatus 100 having been exemplified in the individual embodiments described above can be employed not only in devices that are exclusively used in the printing, but also various devices, such as a facsimile device, a copying machine, and the like. Naturally, the application of the liquid ejecting apparatus according to the invention is not limited to the printing. For example, a liquid ejecting apparatus that ejects solutions of color materials is utilized as a manufacturing apparatus for forming color filters for display apparatuses, such as a liquid crystal display panel and the like. Further, a liquid ejecting apparatus that ejects solutions of conductive materials is utilized as a manufacturing apparatus for forming wirings and electrodes of wiring substrates. Further, a liquid ejecting apparatus that ejects solutions of organic materials related to a living body is utilized as a manufacturing apparatus for manufacturing, for example, biotips.
Number | Date | Country | Kind |
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2017-244255 | Dec 2017 | JP | national |