Liquid discharge head, liquid discharge unit, and recording device

Abstract

A liquid ejection head (3) includes a chip (5) and a rigid wiring board (7). The chip (5) includes a nozzle and an actuator for ejecting liquid from the nozzle. The wiring board (7) supports the chip (5) and is electrically connected to the chip (5).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a liquid ejection head such as an inkjet head, a liquid ejection unit including the liquid ejection head, and a recording device including the liquid ejection head.BACKGROUND OF INVENTION

[0002] Known liquid ejection heads (e.g., inkjet heads) eject liquid (e.g., ink) toward a recording medium (e.g., paper) (see, for example, Patent Literature 1 below). Such heads include, for example, a head body and a flexible board connected to the head body. The head body includes nozzles and actuators that eject liquid (e.g., droplets) from the nozzles. The flexible board contributes to, for example, electrically connecting the actuators to a drive IC (integrated circuit) that drives the actuators.

[0003] The head also includes, for example, multiple head bodies and a frame that supports the multiple head bodies. The multiple head bodies are arranged, for example, in a staggered pattern when viewed from the recording medium. In this way, for example, a head (a so-called line head) having a length spanning the entire width of the recording medium can be realized while using a small head body. The frame is a purely structural member and plays no role from an electrical perspective.CITATION LISTPATENT LITERATURE

[0004] Patent Literature 1: International Publication No. 2021 / 020448SUMMARY

[0005] In an embodiment of the present disclosure, a liquid ejection head includes a chip and a rigid wiring board. The chip includes a nozzle and an actuator configured to eject liquid from the nozzle. The wiring board supports the chip and is electrically connected to the chip.

[0006] In an embodiment of the present disclosure, a liquid ejection unit includes the liquid ejection head and a control board configured as a rigid board and electrically connected to the liquid ejection head. A plurality of the liquid ejection heads is arranged in a lateral direction of the wiring board. Each of the plurality of liquid ejection heads includes a flexible board connected to the wiring board. Portions of the plurality of flexible boards located on a first side in a longitudinal direction of the wiring board with respect to a connection position to the wiring board are connected to the same control board, and the control board is folded back and overlaps the plurality of wiring boards.

[0007] In an embodiment of the present disclosure, a recording device includes the liquid ejection head and a transport device. The transport device moves the liquid ejection head relative to a recording medium onto which liquid ejected from the plurality of nozzles lands.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic perspective view of a recording device according to an embodiment. FIG. 2 is a perspective view schematically illustrating a liquid ejection head of the recording device in FIG. 1. FIG. 3 is an exploded perspective view of the liquid ejection head in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a perspective view schematically illustrating a chip of the liquid ejection head in FIG. 2. FIG. 6 is an exploded perspective view of the chip in FIG. 5. FIG. 7 is a perspective view of a portion of the chip illustrating a cross section taken along line VII-VII in FIG. 5. FIG. 8 is a schematic plan view illustrating an enlarged view of region VIII in FIG. 2. FIG. 9 is a cross-sectional view illustrating another example of a drive IC. FIG. 10 is a perspective view illustrating another example (first example) of a flexible board. FIG. 11 is a perspective view illustrating another example (second example) of a flexible board. FIG. 12 is a perspective view illustrating another example (third example) of a flexible board. FIG. 13 is a perspective view illustrating another example (fourth example) of a flexible board. DESCRIPTION OF EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the drawings used in the following description are schematic drawings. Therefore, for example, the dimensional ratios and so forth in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional ratios and so forth may differ from drawing to drawing. Certain shapes and / or dimensions etc. may be exaggerated, and details may be omitted. However, this does not deny the possibility that the actual shapes and / or dimensions may be as illustrated in the drawings, or that the shapes and / or dimensions may be extracted from the drawings.

[0010] For convenience, a Cartesian coordinate system D1D2D3 may be added to the drawings. A liquid ejection head and a recording device according to an embodiment may be used in any orientation. However, for convenience, terms may be used assuming that the +D3 side is upward.(Outline of Embodiments)

[0011] FIG. 1 is a perspective view schematically illustrating a printer 1 (an example of a recording device) according to an embodiment. The printer 1 is configured as a color printer that forms an image on printing paper P. Specifically, as the printing paper P is transported in a direction D2, four heads 3 (an example of a liquid ejection head) positioned above the printing paper P eject ink (an example of a liquid) toward the printing paper P.

[0012] FIG. 2 is a perspective view of one of the heads 3 (the entirety thereof or at least a portion thereof on the side where the printing paper P is located). FIG. 3 is an exploded perspective view of the head 3. The head 3 includes multiple chips 5 that eject ink droplets (droplets) and directly contribute to printing, and a wiring board 7 (rigid board) that supports the chips 5. When viewed in a direction D3 (viewing the head 3 from the printing paper P), the multiple chips 5 are arranged in staggered pattern in two rows along a direction D1. In this way, for example, a head (a so-called line head) having a length spanning the entire width of the printing paper P can be realized while using small chips 5. Among the multiple chips 5, the ones on the -D2 side may be referred to as chips 5A, and the ones on the +D2 side may be referred to as chips 5B.

[0013] FIG. 5 is a perspective view of one of the chips 5 (5B) as seen from the side where the printing paper P is located. The chip 5 includes multiple nozzles 9 that open toward the side where the printing paper P is located. Ink droplets ejected from the multiple nozzles 9 land on the printing paper P, forming dots that make up an image on the printing paper P. The arrangement of the multiple nozzles 9 is arbitrary. In the example in FIG. 5, the multiple nozzles 9 are arranged in a staggered pattern in two rows along the direction D1 when viewed in the direction D3. This allows dots to be formed on the printing paper P that are arranged in the direction D1 at a pitch that is narrower than the pitch (e.g., the distance between centers) of the nozzles 9 in one row. Among the multiple nozzles 9, the ones on the -D2 side may be referred to as nozzles 9A, and the ones on the +D2 side may be referred to as nozzles 9B.

[0014] FIG. 7 is a perspective view of a portion of the chip 5 (5B) illustrating a cross section taken along line VII-VII in FIG. 5. The chip 5 includes an actuator 11 for each nozzle 9. The actuator 11 applies pressure to the ink to eject ink droplets from the nozzle 9.

[0015] As described in the BACKGROUND OF INVENTION section, in a comparative example, a flexible board is connected to a head body (corresponding to chip 5) including nozzles and actuators. A drive signal (power from another perspective) is input to an actuator via the flexible board. Furthermore, multiple head bodies (5) are supported by a purely structural member (frame).

[0016] On the other hand, in an embodiment, the multiple chips 5 are supported by the wiring board 7. In addition, the wiring board 7 is electrically connected to the chips 5. As a result, for example, the wiring board 7 contributes to inputting of drive signals to the actuators 11. In this way, in an embodiment, the wiring board 7 functions as a member that doubles as the flexible board and the frame in the comparative example. This results in a reduction in the number of components. As a result, for example, reductions in cost and / or size are expected.

[0017] An overview of embodiments has been given above. Hereinafter, an overview and then the details of embodiments are described in the following order. 1. Printers in general (FIG. 1) 2. Heads 2.1. Overall configuration of heads (FIGs. 2 to 4) 2.1.1. Overview of components of heads 2.1.2. Overview of operations of components 2.2. Chips (FIGs. 5 to 7) 2.2.1. Chips in general 2.2.2. Outer shape of chips 2.2.3. Chip terminals 2.2.4. Flow paths and actuators 2.2.5. Chip structure type 2.2.6. Specific example of MEMS chip 2.3. Overview of wiring board 2.4.Driver IC 2.5.Control IC 2.6.Flexible board 2.6.1. Flexible boards in general 2.6.2. Signal board 2.6.3 Power board 2.7. Specific examples of circuits of wiring board (FIG. 8) 2.7.1. Signal-related circuits 2.7.2. Power-related circuits 3. Other examples 3.1. Other examples of drive ICs (FIG. 9) 3.2.Other examples of flexible boards 3.2.1. First example (FIG. 10) 3.2.2. Second example (FIG. 11) 3.2.3. Third example (FIG. 12) 3.2.4. Fourth example (FIG. 13) 3.3. Other matters 4. Summary of embodiments (1. Printers in general)

[0018] As mentioned above, the printer 1 illustrated in FIG. 1 is configured as a so-called line printer. However, the printer 1 is not limited to a line printer. For example, the printer 1 may be a serial printer. In a serial printer, for example, the operation of moving the head in a direction intersecting the transport direction of the printing paper P and transporting the printing paper P are performed in an alternating manner. For convenience, in the description of the embodiments, a line printer may be assumed without being particularly mentioned.

[0019] As mentioned above, the printer 1 includes four heads 3. The part that includes a combination of the four (in other words, multiple) heads 3 and functions as a head may be referred to as a unit 13 (an example of a liquid ejection unit). The four heads 3 are arranged, for example, in the transport direction of the printing paper P. The four heads 3 correspond to inks of different colors (four color inks). The four color inks are, for example, magenta (M), yellow (Y), cyan (C), and black (K). This allows the printer 1 to function as a color printer.

[0020] Unlike in the above description, the printer 1 may print in a single color, or conversely, may print in more than four colors. In other words, the number of colors is arbitrary. Two or more heads 3 may correspond to a single color. In this case, for example, the resolution can be increased. Conversely, one head 3 may correspond to two or more colors. As can be understood from the above description, the number of heads 3 included in the printer 1 is arbitrary.

[0021] The multiple heads 3 included in the unit 13 may be fixed to one another using any suitable method. In the example in FIG. 1, the multiple heads 3 are supported by a support member 15 included in the unit 13, and are thereby fixed to one another. The support member 15 includes, for example, four openings (not illustrated) (i.e., the same number as the number of heads 3) through which the four heads 3 are downwardly exposed.

[0022] The printer 1 prints on, for example, sheets of paper as the printing paper P. However, the printing paper P may also be roll paper. The size of the printing paper P (or, from another perspective, the length of the heads 3 in the direction D1) is also arbitrary. For example, the printing paper P may be as small as a receipt or as large as a poster. As an example, the illustrated sheet of paper serving as the printing paper P may be A3 size as defined by "ISO 216". In other words, the heads 3 may be capable of printing across a length of 297 mm in the direction D1.

[0023] A transport device 17 for transporting the printing paper P (moving the head (3) and the recording medium (P) relative to each other) may have any configuration. In the example in FIG. 1, a configuration is illustrated in which the printing paper P is transported by transporting a belt against which the printing paper P is held. Other configurations include a configuration in which the printing paper P is transported by rotating rollers between which the printing paper P is pinched, and a configuration in which the printing paper P is transported by rotating a drum around which the printing paper P is wrapped.

[0024] In addition to the heads 3 (unit 13 from another perspective) and the transport device 17 already described, the printer 1 may further include a controller 19 that controls the heads 3 and the transport device 17. The controller 19 includes, for example, a computer, and controls the heads 3 and the transport device 17 (a motor 17a thereof) based on print data including image data (which is a broad concept including characters).

[0025] The printer 1 may include any components other than those described above. For example, the printer 1 may include a drying device that accelerates drying of the ink, an application device that uniformly applies a transparent coating agent to the printing paper P, and a cleaning device that cleans the heads 3. Note that the printer 1 may use the heads 3 to apply a coating agent in addition to or instead of printing with colored ink.(2. Heads)(2.1. Overall configuration of heads)(2.1.1. Overview of components of heads)

[0026] Each head 3 illustrated in FIGs. 2 and 3, as described above, includes multiple chips 5 and the wiring board 7 on which the multiple chips 5 are mounted. Unlike in the illustrated example, the head (3) may include only one chip 5. Such a head may be used, for example, as the head of a line printer that prints on relatively small printing paper P (e.g., receipts), or as the head of a serial printer that prints on A3- or A4-sized printing paper P. In the latter case, the longitudinal direction of the chip 5 (direction D1 in FIG. 2) may be the transport direction of the printing paper P (direction D2 in FIG. 1).

[0027] In addition to the multiple chips 5 and the wiring board 7, the head 3 includes, for example, the following components: at least one (multiple in the illustrated example) drive IC 21 that drives the actuators 11 of the multiple chips 5; a control IC 23 that controls the drive IC 21; a flexible board (signal board 25) that inputs control signals from outside the head 3 (from another perspective, the controller 19) to the control IC 23 via the wiring board 7; and at least one (two in the illustrated example) flexible board (power board 27) that applies power (from another perspective, potential) from outside the head 3 to the wiring board 7 and electronic components (e.g., the drive IC 21) mounted on the wiring board 7.

[0028] The multiple drive ICs 21 are arranged in a staggered pattern in two rows, for example, when viewed in the direction D3, so as to be positioned between the multiple chips 5. That is, the multiple chips 5 and the multiple ICs 21 are arranged in an alternating manner in two rows, and form a first row 29A on the -D2 side and a second row 29B on the +D2 side. Among the multiple drive ICs 21, the ones on the -D2 side may be referred to as drive ICs 21A, and the one on the +D2 side may be referred to as drive ICs 21B. The number of drive ICs 21 is, for example, the same as the number of chips 5. Each drive IC 21 controls one chip 5. More specifically, for example, each drive IC 21 controls the chip 5 adjacent thereto in the direction D2.

[0029] The number of power boards 27 is, for example, two. The two power boards 27 are provided, for example, on both sides in the lateral direction (direction D2) of the wiring board 7. Among the two power boards 27, the one on the -D2 side may be referred to as a power board 27A, and the one on the +D2 side may be referred to as a power board 27B.

[0030] The number and arrangement of the drive ICs 21, the control IC 23, the signal board 25, and the power boards 27 may be different from those in the illustrated example. For example, in the illustrated example, the control IC 23 and the power boards 27 are located on one side of the wiring board 7 in the longitudinal direction, but two sets of control ICs 23 and power boards 27 may be provided on both sides of the wiring board 7 in the longitudinal direction.

[0031] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2.

[0032] As illustrated in FIGs. 2 to 4, the multiple chips 5, the drive ICs 21, and the control IC 23 are mounted, for example, on the +D3-side surface of the wiring board 7 (the surface on the opposite side from the printing paper P). The wiring board 7 includes multiple openings 31 (FIGs. 3 and 4) through which the multiple chips 5 are exposed to the -D3 side. This allows the chips 5 to eject ink toward the -D3 side. The signal board 25 and the power boards 27 are bonded to the +D3-side surface of the wiring board 7.

[0033] The head 3 may include components other than those described above. For example, although not specifically illustrated, the following components may be provided: multiple first flow path members that are individually (one-to-one) stacked on the +D3 side of the multiple chips 5 and supply liquid thereto; a second flow path member that is commonly stacked on the +D3 side of the multiple first flow path members and supplies liquid to the multiple first flow path members; a control board that is connected to the wiring board 7 via the signal board 25 and the power boards 27; a heat sink that cools the control board; and a housing that is placed over the wiring board 7 from above and houses the various components described above.

[0034] For example, when the above-mentioned components, which are not illustrated, are provided, only the combination of the components illustrated in the figures may be regarded as a head, or only the chips 5 and the wiring board 7 may be regarded as a head. Furthermore, only the combination of the components illustrated in the figures may be distributed as a head, or only the combination of the chip 5 and the wiring board 7 may be distributed, and the other components may be added later.(2.1.2. Overview of operations of components)

[0035] Print data input to the controller 19 is converted into a drive signal (e.g., pulses) having a waveform corresponding to, for example, the droplet volumes to be ejected (or, from another perspective, the size of the dots to be printed), and input to the actuators 11. In the conversion process, the division of roles among the various processing units from the controller 19 to the actuators 11 may be set as appropriate. An example of the division of roles is described below.

[0036] The controller 19 causes each head 3 to repeatedly eject droplets in a predetermined printing cycle. This operation is combined with the movement of the printing paper P in the direction D2 to form a two-dimensional image. The controller 19 (or a circuit located between the controller 19 and the control IC 23) outputs a control signal to the control IC 23, for example, for each printing cycle, the control signal including information on the volumes of droplets to be ejected from the multiple nozzles 9 (which may be 0). This control signal may be a serial signal or a parallel signal.

[0037] The control IC 23 converts the serial signal (which may be included in parallel signals) contained in the input control signal into parallel signals. This increases the number of control signals transmitted in parallel. The number of control signals output in parallel from the control IC 23 is, for example, greater than or equal to the number of drive ICs 21 (or, from another perspective, chips 5) (for example, an integer multiple of the number of drive ICs 21). In other words, one or more control signals are generated for each drive IC 21. In this case, the control IC 23 may be considered to distribute the input control signal to multiple drive ICs 21, regardless of whether or not conversion circuits 67, which are described later, are present.

[0038] The wiring board 7 includes, for example, the conversion circuits 67 (see FIG. 8, which will be described later). Each conversion circuit 67 is provided for a corresponding drive IC 21. Each conversion circuit 67 converts a serial signal included in the control signal distributed from the control IC 23 to each drive IC 21 (may be a serial signal included in parallel signals distributed to each drive IC 21) into parallel signals and inputs the parallel signals to the drive ICs 21. In other words, the conversion circuit 67 increases the number of control signals transmitted in parallel and inputs the signals to the corresponding drive IC 21. The number of control signals input in parallel to one drive IC 21 is, for example, the same as the number of actuators 11 controlled by one drive IC 21.

[0039] Each drive IC 21 refers to data associating information on the droplet volumes with information on the waveform of the drive signal, and thereby identifies the waveform of the drive signal corresponding to the input control signal for each actuator 11. The drive IC 21 then generates a drive signal having the identified waveform, and outputs the corresponding drive signal to each of the multiple actuators 11 approximately simultaneously.

[0040] The first row 29A and the second row 29B are located at different positions in the direction D2 (the transport direction of the printing paper P). Furthermore, within each chip 5, the nozzles 9A and the nozzle 9B are located at different positions in the direction D2. Depending on the configuration of the chip 5, nozzles 9 included in the same row may be located at different positions in the direction D2. Depending on such differences in the positions of the nozzles 9 in the direction D2, the timing at which droplets corresponding to dots at the same position in the direction D2 are ejected onto the printing paper P differs between the nozzles 9. The division of roles for adjusting this difference in timing is also arbitrary.(2.2. Chips)(2.2.1. Chips in general)

[0041] Each chip 5 may have various configurations, including known configurations or configurations that incorporate known configurations, as long as the chip 5 includes the nozzles 9 and the actuators 11. For example, the method used to eject ink may be a piezoelectric method, a thermal method, or another method. In the piezoelectric method, ink is ejected by applying pressure to the ink through the deformation of a piezoelectric element. In the thermal method, ink is ejected by applying pressure to the ink by heating the ink to generate bubbles. Other methods include, for example, a method that uses electrostatic force to attract charged ink, a method that uses ultrasonic energy, and a method that uses electrostatic force to vibrate the wall of a pressure chamber containing ink.

[0042] As can be understood from the above description, the term "actuator" may be interpreted broadly. That is, the actuator (11) may have various configurations as long as the actuator can convert an input electrical signal into movement of ink (liquid). For example, the actuator (11) may be one that generates displacement, such as a piezoelectric element, one that generates heat, such as a thermal heater, or one that directly applies electrostatic force to ink. In the description of the embodiments, the piezoelectric type will be taken as an example.

[0043] As described above, the multiple chips 5 are arranged in a staggered pattern in two rows, for example. In this case, the total number of chips 5 may be three or more. The total number of chips 5 may be an even number (as in the illustrated example) or an odd number. When viewed in the direction D2, in different rows, the ends of the chips 5 in the direction D1 overlap each other. This allows printing to be performed without gaps in the direction D1. In each row, the pitch (e.g., center-to-center distance) of the multiple chips 5 is approximately constant. The chips 5 may also be arranged in three or more rows.

[0044] The size of the chips 5 is arbitrary. The size of the chips 5 may be set from various viewpoints, such as ease of manufacturing, processing precision, and ensuring strength. For example, the length of the chips 5 (direction D1) may be 40 mm or more and 60 mm or less. The width of the chips 5 (direction D2) may be 3 mm or more and 5 mm or less. The thickness of the chips 5 (direction D3) may be 0.5 mm or more and 2 mm or less.

[0045] The number of chips 5 is arbitrary. The number of chips 5 may be set, for example, according to the length of the chips 5 in the direction D1 (the direction perpendicular to the direction of relative movement with the printing paper P) and the length of the head 3 in the direction D1 (or, from another perspective, the length of the printing paper P in the direction D1). In the example in FIGs. 2 and 3, assuming the size of the chips 5 exemplified in the previous paragraph and A3 size printing paper P (length in the direction D1 is 297 mm), four chips 5 are provided in each row, giving a total of eight chips 5.

[0046] The dot density (image resolution) achieved by the chips 5 is arbitrary. From another perspective, the arrangement pattern, number, etc. of the multiple nozzles 9 are arbitrary. Examples of dot density etc. are as follows. One chip 5 may include multiple nozzles 9 in an arrangement pattern and number such that the dot density in the direction D1 is 600 dpi or more and 2000 dpi or less. Furthermore, the number of nozzles 9 in one chip 5 may be 100 or more and 10,000 or less.

[0047] Since FIG. 5 is a schematic diagram, the nozzles 9 are illustrated to be large relative to the size of the chip 5 and the number of nozzles 9 per chip 5 is illustrated to be small. In reality, the nozzles 9 may be smaller and the number of nozzles 9 may be greater than in FIG. 5. In addition, in the description of the number of nozzles 9 (or the number of other elements corresponding to the number of nozzles 9) in the description of the embodiments, the existence of so-called dummy nozzles that do not eject ink is ignored for convenience.

[0048] As described above, the arrangement pattern of the multiple nozzles 9 is arbitrary, and the arrangement of the nozzles 9 illustrated in FIG. 5 is merely one example. For example, the multiple nozzles 9 may be arranged in one row, or in three or more rows, or may be inclined with respect to the direction D1. In each row, the multiple nozzles are arranged at a constant pitch, but some amount of randomness may be intentionally imparted. The multiple nozzles 9 arranged in two or more rows are, for example, arranged at different positions in the direction D1, and this contributes to improved resolution. In a specific embodiment, the chip 5 may include only one nozzle 9.(2.2.2. Outer shape of chips)

[0049] The outer shape of the chips 5 is arbitrary. In the example in FIGs. 2 to 5, the chips 5 have a roughly thin rectangular parallelepiped shape with the direction D1 as the longitudinal direction and the direction D3 as the thickness direction. More specifically, as illustrated in FIGs. 4 and 5, each chip 5 has a rectangular parallelepiped-shaped main body 5e and two flanges 5f protruding on both sides, in the direction D2, from the +D3 side (opposite side from the nozzles 9) of the main body 5e. The lower surface of the main body 5e forms a nozzle surface 5a where the multiple nozzles 9 open.

[0050] The main body 5e is inserted into the corresponding opening 31 from the +D3 side. This brings nozzle surface 5a closer to the printing paper P than the upper surface of the wiring board 7. The nozzle surface 5a may be positioned above the lower surface of wiring board 7 (example in FIG. 4), may be flush with the lower surface of wiring board 7, or may be positioned below the lower surface of wiring board 7. The main body 5e may contribute to positioning of the chip 5 and the wiring board 7, for example, by abutting against the inner peripheral surface of the opening 31, or may not contribute to such positioning.

[0051] The flanges 5f engage with the wiring board 7 from the +D3 side around the periphery of the opening 31. That is, the flanges 5f contribute to positioning the chip 5 in the direction D3 relative to the wiring board 7 when the main body 5e is inserted into the opening 31. Furthermore, as will be described in detail later, the flanges 5f contribute to fixing and / or electrically connecting the chip 5 to the wiring board 7 as a result of the lower surfaces thereof being joined to the upper surface of the wiring board 7.

[0052] Unlike in the illustrated example, the shape of the chip 5 may be, for example, a rectangular parallelepiped shape. That is, the nozzle surface 5a may be located higher than the upper surface of the wiring board 7. Furthermore, in addition to or instead of the direction D2, flanges may be provided in the direction D1. In addition to or instead of the flanges 5f, the outer peripheral surface of the main body 5e and the inner peripheral surface of the opening 31 may be joined to each other, and fixed and / or electrically connected to each other.(2.2.3. Chip terminals)

[0053] The manner in which each chip 5 and the wiring board 7 are electrically connected to each other is arbitrary. In other words, the form of the terminals of the chip 5 is arbitrary. In the illustrated example, the chip 5 includes multiple terminals 35 (FIG. 5) composed of layer-shaped conductors on the lower surfaces of the flanges 5f. Meanwhile, the wiring board 7 includes pads 37 (FIG. 4) around the opening 31 that are bonded to the terminals 35. The terminals 35 and the pads 37 are bonded to each other while facing each other, thereby electrically connecting the two together.

[0054] Unlike in the illustrated example, for example, terminals located on the upper surface of chip 5 and pads located on the upper surface of wiring board 7 may be connected to each other by bonding wires. Furthermore, for example, pin-shaped terminals protruding from the chip 5 may be bonded to pads located on the upper surface of wiring board 7. In addition, for example, pins protruding from the chip 5 may be inserted into the wiring board 7 in order to perform through-hole mounting.

[0055] The terminals 35 and the pads 37 may be bonded to each other using any method. For example, ACF (anisotropic conductive film) connections may be used. More specifically, for example, thermocompression bonding may be performed with an ACF sandwiched between substantially the entire lower surfaces of the flanges 5f and the upper surface of the wiring board 7. The portions of the ACFs sandwiched between the terminals 35 and the pads 37 may contribute to fixation and electrical connection. The rest of the ACFs may contribute to fixation (and insulation).

[0056] Alternatively, the terminals 35 and the pads 37 may be bonded to each other using solder or a conductive adhesive. As can be understood from the description stating that bonding wires may be used, the chip 5 and the wiring board 7 may be fixed together using an insulating adhesive.

[0057] The terminals 35 include, for example, multiple terminals 35D to which drive signals for driving the actuators 11 are input, and at least one terminal 35G (FIG. 4) to which a reference potential is applied. When driving the actuators 11, the potential difference between the reference potential and the drive signal is utilized.

[0058] The number of terminals 35D is basically (except for special cases) the same as the number of actuators 11 (from another perspective, the nozzles 9). The multiple terminals 35D are connected in an individual (one-to-one) manner to the multiple actuators 11. In this way, ejection of liquid from each nozzle 9 is controlled. The number of terminals 35G is arbitrary and may be one or more. In the latter case, the number of terminals 35G may be the same as the number of the terminals 35D, or may be different (for example, may be fewer).

[0059] The specific shapes, dimensions, and arrangement of the terminals 35D and 35G are arbitrary. In the example in FIG. 5, all of the terminals 35D are located on the flange 5f adjacent to the drive IC 21 in the direction D2 (the -D2 side for the chips 5B and the +D2 side for the chips 5A). All of the terminals 35G are located on the flange 5f on the opposite side. The multiple terminals 35D have, for example, the same shape and dimensions as each other and are arranged at a constant pitch in the direction D1 (the longitudinal direction of the chip 5). The multiple terminals 35G have, for example, the same shape and dimensions as each other and are arranged at a constant pitch. The shape, dimensions, and / or pitch of the multiple terminals 35G may be the same as or different from those of the terminals 35D. A single terminal 35G that is long in the direction D1 may be provided.(2.2.4. Flow paths and actuators)

[0060] As can be understood from the above description, ink flow paths (including the nozzles 9) and the actuators 11 may have any configuration. An example is described below.

[0061] FIG. 6 is an exploded perspective view of the chip 5 (5B).

[0062] As illustrated in FIGs. 6 and 7, a common flow path 47 opens at the upper surface of the chip 5. Ink is supplied to the common flow path 47 from a flow path member, which is not illustrated, that is stacked on the upper surface of the chip 5. As illustrated in FIG. 7, multiple individual flow paths 49 communicate with the common flow path 47. Each individual flow path 49 includes, in this order from the common flow path 47 side, a supply path 49a, a pressure chamber 51, and the nozzle 9. The pressure chamber 51 is replenished with ink from the common flow path 47 via the supply path 49a. When pressure is applied to the pressure chamber 51 by the actuator 11, liquid is ejected from the nozzle 9.

[0063] The specific shapes and dimensions of the common flow path 47 and the multiple individual flow paths 49 are arbitrary. In the illustrated example, the common flow path 47 extends linearly in the longitudinal direction of the chip 5 at a position at the center of the chip 5 in the width direction. The multiple individual flow paths 49 generally extend from the common flow path 47 toward one side or the other in the width direction of the chip 5, and the corresponding nozzle 9 is positioned at the tip of each of the individual flow paths 49. The nozzle 9 opens directly into the pressure chamber 51.

[0064] Unlike in the illustrated example, for example, two common flow paths 47 may be provided on both sides of the chip 5 in the width direction. Multiple individual flow paths 49 may extend from the common flow path on one side or the other side of the chip 5 in the width direction toward the center of the chip 5 in the width direction. In addition, a flow path may be interposed between each nozzle 9 and the corresponding pressure chamber 51. The chip 5 may include a flow path for recovering ink.

[0065] The actuator 11 illustrated in FIG. 7 is a so-called unimorph type piezoelectric actuator. The actuator 11 includes, for example, a vibration plate 53, a lower electrode 55, a piezoelectric body 57, and an upper electrode 59, in this order from the side where the pressure chamber 51 is located. These components, for example, substantially cover the pressure chamber 51. The piezoelectric body 57 is polarized in the thickness direction.

[0066] When a voltage is applied to the piezoelectric body 57 in the thickness direction by the lower electrode 55 and the upper electrode 59, the piezoelectric body 57 expands or contracts in the planar direction. This deformation is restricted by the vibration plate 53, and therefore the actuator 11 bends toward the pressure chamber 51 or toward the opposite side like a bimetal. This bending deformation is used to apply pressure to the pressure chamber 51, and this causes ink to be ejected from the nozzle 9.(2.2.5. Chip structure type)

[0067] The outer shapes of the chips 5, the terminals 35, the flow paths (47 and 49), the actuators 11, and the like described above may be realized using any of various structural forms. For example, each chip 5 may be configured by a MEMS (micro electro mechanical systems) chip. A MEMS chip includes, for example, one or more chip substrates on which mechanical elements and / or electrical elements are formed by microfabrication techniques on a base substrate. Two or more chip substrates may be stacked, for example. The base substrate may be, for example, a silicon substrate. However, the material of the base substrate may be a material other than silicon (for example, glass or an organic material). The mechanical and electrical elements of the chip substrate, for the chip 5, include, for example, the flow paths (47 and 49), the actuators 11, and the terminals 35.

[0068] In a MEMS chip including multiple chip substrates, each chip substrate may include only one of mechanical elements and electrical elements. From another perspective, the mechanical elements and electrical elements may be provided on separate substrates. When the MEMS chip is a multilayer body consisting of multiple substrates, all of the multiple substrates may be MEMS-related chip substrates, or only some of the substrates may be MEMS-related chip substrates.

[0069] Microfabrication techniques related to MEMS are usually performed with a mother substrate (wafer) from which a large number of base substrates are obtained. Examples of microfabrication techniques include: thin film formation by PVD (physical vapor deposition, e.g., sputtering), CVD (chemical vapor deposition), or ALD (atomic layer deposition); patterning of the thin films using photolithography; and etching of the base substrates using photolithography. The precision of the microfabrication may be, for example, 20 µm or less, 10 µm or less, or 2 µm or less in plan view.

[0070] Unlike in the above description, the chip 5 does not need to be a MEMS chip. For example, the chip 5 may be formed by bonding a flow path member including the nozzles 9 and an actuator substrate including the actuators 11 together. In this case, the flow path member may be formed by bonding a plurality of stacked plates (metal plates and / or resin plates) together with an adhesive. Each plate may include recesses and / or through holes that will become the flow paths formed by wet etching. The actuator substrate may be fabricated by stacking and firing ceramic green sheets to which a conductive paste has been applied in predetermined patterns.(2.2.6. Specific example of MEMS chip)

[0071] When the chip 5 is configured by a MEMS chip, the specific configuration thereof is arbitrary. An example is described below.

[0072] As illustrated in FIG. 6, the chip 5 is configured, for example, by stacking multiple (four in the illustrated example) chip substrates (already described) in the direction D3 and bonding them together. More specifically, a nozzle substrate 39, an actuator substrate 41, a support substrate 43, and a relay substrate 45 are stacked in this order from the -D3 side (the side where the printing paper P is located).

[0073] The nozzle substrate 39 includes, for example, multiple nozzles 9. The actuator substrate 41 includes, for example, multiple actuators 11, and flow paths that supply ink to the multiple nozzles 9. The support substrate 43, for example, contributes to the reinforcement of the nozzle substrate 39 and the actuator substrate 41, and includes flow paths and circuits (which may be simple wiring) that lead to the flow paths and circuits of the actuator substrate 41. The relay substrate 45 includes, for example, flow paths and circuits that lead to the flow paths and circuits of the support substrate 43, and also includes the flanges 5f.

[0074] These chip substrates may be bonded together using an appropriate bonding method. For example, the chip substrates may be directly bonded to each other without an adhesive, or may be bonded to each other using an adhesive. Note that in FIG. 7, illustration of an adhesive may be omitted regardless of whether or not the substrates are directly bonded to each other. The thickness of each chip substrate may be set as appropriate depending on the functions required of each chip substrate, or the like. For example, the thickness of each of the nozzle substrate 39 and the actuator substrate 41 is 20 µm or more and 100 µm or less. The thickness of each of the support substrate 43 and the relay substrate 45 is 200 µm or more and 1000 µm or less.

[0075] Each chip substrate (39, 41, 43, and 45) is configured as described below, for example.

[0076] As illustrated in FIG. 7, the nozzle substrate 39 is configured by forming multiple nozzles 9 in a base substrate using microfabrication techniques. The base substrate is, for example, a silicon substrate. The shape and dimensions etc. of the nozzles 9 are arbitrary.

[0077] The actuator substrate 41 (FIG. 7) is configured by forming a multilayer film 41b on a base substrate 41a using microfabrication techniques. The multilayer film 41b includes the actuators 11.

[0078] The base substrate 41a is, for example, a silicon substrate. The pressure chambers 51 and parts of the supply paths 49a are formed in the base substrate 41a using microfabrication techniques. The specific shapes and dimensions etc. of the pressure chambers 51 and the supply paths 49a are arbitrary.

[0079] The multilayer film 41b includes, for example, at least four layers including the above-mentioned vibration plate 53, the lower electrodes 55, the piezoelectric bodies 57, and the upper electrodes 59. Although not particularly illustrated, the multilayer film 41b may include layers other than those described above. For example, the multilayer film 41b may include an insulating layer that covers a metal layer so that ink does not contact the metal layer, or an insulating layer that covers a metal layer including the lower electrodes 55 and a metal layer including the upper electrodes 59 in order to insulate these layers from each other.

[0080] The vibration plate 53 may, for example, extend over the entire base substrate 41a (as in the illustrated example), or may not extend over the entire base substrate 41a. Unlike in the illustrated example, the vibration plate 53 may be provided for each pressure chamber 51. The vibration plate 53 closes the top of the pressure chambers 51. In the example in FIG. 7, the vibration plate 53 also contributes to closing the portions of the supply paths 49a formed in the base substrate 41a. The vibration plate 53 (or, from another perspective, the multilayer film 41b) includes through-holes (see also FIG. 6) that form portions of the supply paths 49a that lead to the common flow path 47. The material of the vibration plate 53 is arbitrary, and may be, for example, an insulating material or the same material as the piezoelectric bodies 57.

[0081] For example, a reference potential is applied to the lower electrodes 55. From another perspective, a common potential is applied to the lower electrodes 55 of the multiple actuators 11. Therefore, the lower electrodes 55 of the multiple actuators 11 may be connected to each other. In the example in FIG. 7, the lower electrode 55 is provided for each pressure chamber 51. Unlike in the illustrated example, the lower electrode 55 may extend across the multiple pressure chambers 51.

[0082] In the example in FIG. 7, the metal layer (reference potential layer) including each lower electrode 55 includes, for example, wiring (reference symbol omitted) extending from the lower electrode 55 toward the side where the already-described terminal 35G is located (the +D2 side in the chip 5B), and a terminal 61G (see also FIG. 6) located at the end of the wiring. The terminal 61G is connected to the terminal 35G via a support substrate 34. In the example in FIG. 6, the terminal 61G is commonly used by multiple actuators 11.

[0083] Unlike in the illustrated example, multiple terminals 61G may be formed individually for the multiple actuators 11. The metal layer including the lower electrodes 55 and the terminal 61G may extend over substantially the entire surface of the base substrate 41a. In this case, the metal layer including the lower electrodes 55 and the metal layer including the upper electrodes 59 may be insulated from each other by an insulating layer (or a layer including the piezoelectric body 57), which is not illustrated.

[0084] The piezoelectric body 57 may or may not (illustrated example) extend over the entire base substrate 41a. In the example in FIG. 7, the piezoelectric body 57 is provided for each pressure chamber 51. In a plan view, the shape and size of each piezoelectric body 57 are approximately the same as the shape and size of the corresponding pressure chamber 51. The specific material of the piezoelectric body 57 is arbitrary, and is, for example, lead zirconate titanate (PZT).

[0085] A drive signal, for example, is input to the upper electrodes 59 (individual electrodes). From another perspective, different potentials are applied to the upper electrodes 59 of the multiple actuators 11. The upper electrodes 59 of the multiple actuators 11 are provided for each pressure chamber 51 and are not connected to each other. The upper electrodes 59 have, for example, substantially the same shape and size as the pressure chambers 51 plan view.

[0086] In the example in FIG. 7, the metal layer including each upper electrode 59 includes, for example, wiring (reference symbol omitted) extending from the upper electrode 59 to the side where the already-described terminal 35D is located (the -D2 side in the chip 5B), and a terminal 61D (see also FIG. 6) located at the end of the wiring. The terminal 61D is connected to the terminal 35D via the support substrate 34.

[0087] The support substrate 43 is configured by forming appropriate shapes and conductors in a base substrate (reference symbol omitted) using microfabrication techniques. As previously described, the base substrate is, for example, a silicon substrate. The shapes formed in the base substrate are, for example, a through-hole (slit) that forms a lower portion of the common flow path 47, and recesses (grooves) that accommodate the actuators 11 and are formed on the underside of the base substrate. The conductors formed in the base substrate are, for example, through conductors 43b that connect the terminals 61D and 61G of the actuator substrate 41 to the terminals 35D and 35G on the lower surfaces of the flanges 5f.

[0088] The relay substrate 45 is formed to be wider in the direction D2 than the support substrate 43. As a result, the previously described flanges 5f are formed by edge portions of the relay substrate 45. The relay substrate 45 is formed by forming appropriate shapes and conductors in and on a base substrate (reference symbol omitted) using microfabrication techniques. As previously described, the base substrate is, for example, a silicon substrate. The shapes formed in the base substrate include, for example, a through-hole (slit) that forms an upper part of the common flow path 47. The conductors formed on the base substrate are, for example, the previously described terminals 35D and 35G.

[0089] The actuator substrate 41 and the support substrate 43 are bonded together via, for example, an ACF 63. As a result, the multiple terminals 61D and 61G of the actuator substrate 41 are electrically connected to the multiple through conductors 43b of the support substrate 43 in an individual manner. The support substrate 43 and the relay substrate 45 are bonded together via, for example, an ACF 65. As a result, the multiple through conductors 43b of the actuator substrate 41 are electrically connected to the multiple terminals 35D and 35G of the relay substrate 45 in an individual manner.(2.3. Overview of wiring board)

[0090] The wiring board 7 illustrated in FIGs. 2 to 4 may be any type of wiring board, as long as the wiring board 7 is a rigid board. For example, the wiring board 7 may be a single-sided board including a conductor layer on only one side of an insulating substrate, a double-sided board including conductor layers on both sides of an insulating substrate, or a multilayer board including three or more conductor layers. Furthermore, when the wiring board 7 includes two or more conductor layers, the wiring board 7 may be a build-up type board in which insulating layers and conductor layers are sequentially formed on the top surface of an insulating substrate serving as a core, or may be a type of board in which combinations of insulating layers and conductor layers are bonded together. The material of the insulating substrate is arbitrary, and may be, for example, resin, ceramic, or glass.

[0091] In one example, the wiring board 7 may be an LTPS (low temperature polycrystalline silicon) substrate. An LTPS substrate is fabricated, for example, by poly crystallizing amorphous silicon deposited on a glass substrate at a low temperature of 600°C or less using laser annealing or the like. That is, although not specifically illustrated, the LTPS substrate includes a glass substrate and an LTPS layer stacked on the glass substrate. A circuit including elements such as TFTs (thin film transistors) may be configured by doping the LTPS layer, forming a thin film (e.g., a metal film and / or an insulating film), patterning the thin film, or the like. A circuit including an LTPS layer is sometimes referred to as an LTPS circuit.

[0092] The patterns of the conductor layers of the wiring board 7 (or, from another perspective, the circuit configuration) may be any patterns so long as the patterns allow the chips 5 to be mounted and allow the chips 5 to be electrically connected to other electrical elements (here, the drive ICs 21). In the illustrated example, the wiring board 7 is configured so that the drive ICs 21 and the control IC 23 can be mounted thereon. Unlike in the illustrated example, for example, the wiring board 7 may be configured to simply act as an intermediary between the chips 5 and a flexible board, with the drive ICs 21 etc. being mounted on the flexible board. Even in this case, the degree of freedom with respect to the connection positions and shape of the flexible board is improved compared to, for example, an embodiment in which a flexible board is connected to multiple chips 5.

[0093] The wiring board 7 (the circuit thereof) may simply include wiring, or may include electronic elements. The electronic elements may be, for example, passive elements or active elements. Furthermore, the electronic elements may be, for example, switches, registers, latch circuits, ICs, or power supply circuits. When the wiring board 7 includes electronic elements, the electronic elements may be either built-in or embedded electronic elements. The former type of electronic elements are, for example, manufactured so as to be integrated with the substrate portion of the wiring board 7 when the wiring board 7 is manufactured. In the latter type of electronic elements, for example, pre-manufactured electronic elements (e.g., IC chips) are embedded in the substrate portion of the wiring board 7 when the wiring board 7 is manufactured.

[0094] In the illustrated example, as described above, the wiring board 7 includes the conversion circuit 67 that increases the number of control signals transmitted in parallel (performs serial-parallel conversion). The conversion circuit 67 may be, for example, a built-in type circuit. More specifically, the conversion circuit 67 may be, for example, configured as an LTPS circuit included in an LTPS substrate serving as the wiring board 7.

[0095] The size and shape of the wiring board 7 are arbitrary. For example, the shape of the wiring board 7 is generally rectangular with the direction D2 as the longitudinal direction. That is, the wiring board 7 has a pair of long edges 7a and a pair of short edges 7b, as indicated by the reference symbols in FIG. 3. As an example of the dimensions, the length of the wiring board 7 in the direction D1 corresponds to the width of the A3 size, and is 300 mm or more and 400 mm or less. The width (direction D2) is 10 mm or more and 20 mm or less. The thickness is 0.5 mm or more and 1 mm or less. The shape and dimensions of the openings 31 are generally the same as the shape and dimensions of the main body 5e of the chips 5 in plan view.

[0096] As can be understood from the above description, the wiring board 7 relays signals from the signal board 25 to the chips 5. More specifically, the relaying of signals includes the following: relaying of control signals from the signal board 25 to the control IC 23; relaying of control signals from the control IC 23 to the conversion circuits 67; relaying of control signals from the conversion circuits 67 to the drive ICs 21; and relaying of drive signals from the drive ICs 21 to the chips 5. The arrangement or the like of wiring related to these relay operations is arbitrary. An example will be described later (FIG. 8).

[0097] Furthermore, the wiring board 7 distributes the power supplied from the power boards 27 (from another perspective, a reference potential and a potential having a predetermined potential difference from the reference potential) to, for example, the circuits (e.g., the conversion circuits 67), the drive ICs 21, and the control IC 23 of the wiring board 7. Furthermore, the wiring board 7 applies the reference potential applied from the power boards 27 to, for example, the terminal 35G of the chips 5 (from another perspective, the lower electrode 55). The arrangement or the like of the wiring related to these power supply operations is arbitrary. An example will be described later (FIG. 8). In the description of the embodiments, the potential having a predetermined potential difference from the reference potential for power supply may be referred to as a "power supply potential".(2.4. Drive ICs)

[0098] The drive ICs 21 illustrated in FIGs. 2 to 4 are, for example, chip-type components. Each drive IC 21 may include a package surrounding a semiconductor substrate, or may be a bare chip without a package. The manner in which the drive IC 21 is mounted is arbitrary. In the example illustrated in FIG. 4, the drive IC 21 includes terminals 21a (an example of input sections) composed of layer-shaped conductors on the lower surface thereof, and is surface-mounted on the wiring board 7. Other configurations include, for example, the various configurations described in the description of the chips 5 (mounting using bonding wires, surface mounting with pin-shaped terminals, or through-hole mounting). The bonding material used in the surface mounting is also arbitrary. In the illustrated example, bonding is performed using ACF, which is not illustrated, similarly to the chips 5. Of course, solder or a conductive adhesive may also be used. As can be understood from the above description, the drive IC 21 may be mounted using COG (chip-on-glass) mounting.

[0099] The shape and dimensions of the drive ICs 21 are also arbitrary. In the illustrated example, each drive IC 21 is roughly shaped like a thin rectangular parallelepiped with the direction D1 as the longitudinal direction and the direction D3 as the thickness direction. In the illustrated example, the drive ICs 21 are assumed to be disposed between the multiple chips 5 arranged in a staggered pattern. Therefore, the length of each drive IC 21 in the direction D1 is smaller than the length of the chips 5 in the direction D1 and is also smaller than the distance between adjacent chips 5 in the direction D1. The width (direction D2) of the drive IC 21 may be smaller (in the illustrated example), equal to, or larger than the width (direction D2) of the chips 5. The thickness of the drive IC 21 may be smaller than, equal to, or greater than the overall thickness of the chips 5 or the thickness of the flanges 5f of the chips 5.

[0100] As described above, the number of drive ICs 21 is, for example, the same as the number of chips 5, and the drive ICs 21 are disposed between the chips 5 arranged in a staggered pattern. Unlike in the illustrated example, the number of drive ICs 21 may be greater than or less than the number of chips 5. Furthermore, the number of drive ICs 21 may be one. Furthermore, the drive ICs 21 do not need to be positioned between the chips 5. For example, the drive ICs 21 may be located only at one end or both ends of the wiring board 7 in the longitudinal direction.

[0101] In each row of the staggered arrangement, the pitch of the drive ICs 21 in the direction D1 is, for example, substantially constant and substantially the same as the pitch of the chips 5 in the direction D1. The positions in the direction D1 of the centers of the drive ICs 21 and chips 5 adjacent to each other in the direction D2 substantially coincide with each other.

[0102] When each row (29A and 29B) is viewed in the direction D1, the drive ICs 21 may fit within the width (direction D2) of the chips 5 (as in the illustrated example), or may not fit on the +D2 side and / or the -D2 side. In either case, the drive ICs 21 may be offset toward the adjacent long edge 7a (for example, the -D2 side in the first row 29A) or toward the opposite side relative to the width of the chips 5 (as in the illustrated example), or may not be offset.

[0103] In the illustrated example, the arrangement range of the drive ICs 21 in the direction D2 is roughly the same as the arrangement range of the chips 5 in the direction D2 but narrowed toward the adjacent long edge 7a. This ensures that, for example, the width of each row (29A and 29B) is within the width of the chips 5, while also ensuring an area in which to form wiring lines 81 (see FIG. 8) that connect each drive ICs 21 and the corresponding chip 5 adjacent thereto in the direction D2.

[0104] Each drive IC 21 outputs a drive signal to the upper electrodes 59 (individual electrodes) of the actuators 11 via the wiring board 7. The drive signal is, for example, a signal having a waveform that causes the actuators 11 to bendingly deform (and / or release the bending deformation) and is generally pulsed. An example of the process through which print data is converted into a drive signal has already been described. In addition to the control signal, the drive IC 21 is also supplied with a reference potential and a power supply potential of a predetermined magnitude via, for example, the power board 27 and the wiring board 7. In other words, a DC voltage of a predetermined magnitude is supplied. The drive IC 21 generates a drive signal of a desired waveform from the DC voltage, for example.(2.5. Control IC)

[0105] The description of the drive ICs 21 may be applied to the control IC 23 as appropriate, except for the location and role thereof. To be clear, the control IC 23 is a chip-type component and may or may not be a bare chip. The mounting method is arbitrary, and may or may not be COG mounting. The shape, dimensions, and mounting location of the control IC 23 are arbitrary.

[0106] In the example in FIGs. 2 and 3, the control IC 23 is smaller in size than the chips 5 and the drive ICs 21. Of course, this does not need to be the case. Furthermore, in the illustrated example, only one control IC 23 is provided. However, two or more control ICs 23 may be provided.

[0107] In the illustrated example, the control IC 23 is located at an end portion (+D1 side) of the wiring board 7 in the longitudinal direction relative to the chips 5 and the drive ICs 21. The position of the control IC 23 in the width direction (direction D2) of the wiring board 7 is made to be at the center of the wiring board 7 in the width direction. Of course, the arrangement position of the control IC 23 is not limited to that described above. For example, the control IC 23 may be adjacent to the +D1 side of the drive IC 21 that is furthest toward the +D1 side among the ICs 21 arranged in a staggered pattern, or may be adjacent to the chip 5 furthest toward the +D1 side in the direction D2.(2.6. Flexible board)(2.6.1. Flexible substrates in general)

[0108] Flexible boards (signal board 25 and power boards 27 illustrated in FIGs. 2 and 3) connected to the wiring board 7 do not need to be provided. For example, instead of a flexible board, a connector into which another rigid substrate is inserted may be mounted on the wiring board 7. Furthermore, the flexible boards do not need to be provided in combination with the signal board 25 and the two power boards 27. For example, one flexible board having the functions of the signal board 25 and the power boards 27 may be provided.

[0109] The flexible boards (25 and 27) may be any type of board. For example, the flexible boards may have a conductor layer on only one side of a film (as illustrated in the example), may have conductor layers on both sides of a film, or may include three or more conductor layers.

[0110] The flexible boards (25 and 27), for example, merely function as wiring for supplying signals and / or power, and do not have any electronic components mounted thereon. Contrary to the description here, the flexible boards may include circuits that function as active elements or the like, or may include electronic components (e.g., ICs) mounted thereon.

[0111] The thickness of the flexible boards (25 and 27) is arbitrary, for example, 0.2 mm or less. The thickness of the conductor layers (or, from another perspective, the wiring) of the flexible boards is also arbitrary. For example, the thickness of the conductor layers of the flexible boards (25 and 27) is greater than the thickness of the conductor layers of the wiring board 7 (for example, an LTPS substrate). This makes the wiring resistance of the power boards 27 smaller than that of the wiring board 7, reducing the likelihood of a drop in the power supply potential.

[0112] The flexible boards (25 and 27) may be joined to the wiring board 7 using any method. For example, ACF connection may be used. Of course, solder or a conductive adhesive may also be used.(2.6.2. Signal board)

[0113] As can be understood from the above description, the signal board 25 inputs a control signal (already described) from the controller 19 (or a circuit located between the controller 19 and the signal board 25) to the control IC 23 via the wiring board 7. The signal input to signal board 25 may be output directly from signal board 25, or may be output after undergoing predetermined processing (e.g., amplification and / or serial-to-parallel conversion).

[0114] The signal board 25 may be connected to the wiring board 7 at any position. In the illustrated example, the signal board 25 is joined to the wiring board 7 at a position closer to the short edge 7b on the +D1 side than the control IC 23 in the longitudinal direction of the wiring board 7 (the opposite side from the multiple chips 5 and multiple drive ICs 21). More specifically, the joining area is roughly the end portion of the wiring board 7 on the +D1 side. The position of the connection position in the direction D2 is made to be at the center of the width of the wiring board 7. Unlike in the illustrated example, the connection position of the signal board 25 may be, for example, on the -D2 side and / or +D2 side of the control IC 23.

[0115] The direction in which the signal board 25 extends (spreads) from the connection position with the wiring board 7 is arbitrary. In the illustrated example, the signal board 25 extends from the connection position toward the +D1 side. From another perspective, the portion (end portion) of the signal board 25 located on the +D1 side of the joining position of the wiring board 7 is a connection portion 25a (reference symbol illustrated in FIG. 2) that is connected to another component on the controller 19 side. Unlike in the illustrated example, the signal board 25 may extend, for example, toward the -D2 side and / or the +D2 side from the connection position.

[0116] The shape and dimensions of the signal board 25 are arbitrary. In the illustrated example, the signal board 25 has roughly rectangular planar shape, more specifically, a rectangular shape with the direction D1 as the longitudinal direction. When the signal board 25 is not bent and is arranged flat parallel to the wiring board 7, the signal board 25 fits within the width of the wiring board 7 and extends out from the +D1-side short edge 7b of the wiring board 7 toward the +D1 side. Unlike in the illustrated example, the signal board 25 does not need to have such a width and length.(2.6.3. Power board)

[0117] The power boards 27 supply power (e.g., DC power of a predetermined voltage) supplied from a power supply circuit, which is not illustrated, included in the main body or the heads 3 of the printer 1 to the wiring board 7. The power input to the power boards 27 may be output directly from the power boards 27, or may be output after undergoing predetermined processing (e.g., transformation and / or division into powers of different voltages).

[0118] The connection positions where the power boards 27 are connected to the wiring board 7, the direction in which power boards 27 extend from the connection positions, and the shape and dimensions of the power boards 27 are arbitrary. In the examples in FIGs. 2 and 3, they are as follows.

[0119] The connection positions of the power board 27A on the -D2 side are located in the region between the first row 29A on the -D2 side and the long edge 7a on the -D2 side. Similarly, the connection positions of the power board 27B on the +D2 side are located in the region between the second row 29B on the +D2 side and the long edge 7a on the +D2 side. Furthermore, as will be described later with reference to FIG. 8, in each region, multiple connection positions are regularly distributed over a relatively long range in the direction D1 (for example, a length equal to or greater than two-thirds of the length of each row).

[0120] Each power board 27 extends from the above-mentioned multiple connection positions toward one side in the longitudinal direction of the wiring board 7 (the -D1 side in the illustrated example). The above-mentioned one side is opposite to the side from which the signal board 25 extends. From another perspective, the portion (end portion) of each power board 27 located on the -D1 side of the multiple connection positions to the wiring board 7 is a connection portion 27a (reference symbol in FIG. 2) that is connected to other components on the side where the controller 19 is located. When the power boards 27 are not bent and is arranged flat parallel to the wiring board 7, the power boards 27 have a length that extends beyond the short edge 7b on the -D1 side of the wiring board 7. However, the signal board 27 does not need to have such a length.

[0121] Let us assume that the power board 27A is not bent and is arranged flat parallel to the wiring board 7. In this case, the power board 27A is shaped to extend linearly in the direction D1 with a substantially constant width (in other words, an elongated shape that follows the long edge 7a on the -D2 side). Furthermore, in plan view, the power board 27A is contained within the region between the first row 29A (from another perspective, the multiple chips 5A and / or the multiple drive ICs 21A) and the long edge 7a on the -D2 side (does not protrude beyond the long edge 7a on the -D2 side). In this case, the edge of the power board 27A on the -D2 side may overlap the long edge 7a on the -D2 side or may protrude beyond the long edge 7a on the -D2 side within a tolerance range. Unlike in the illustrated example, the power board 27A may not protrude beyond the long edge 7a on the -D2 side but may overlap the drive ICs 21 and / or chips 5. Although the power board 27A has been described, the same or a similar description applies to the power board 27B. However, the first row 29A and the word - D2 are replaced with the second row 29B and the word +D2.(2.7. Specific examples of circuits of wiring board)

[0122] As described above, the wiring board 7 relays signals and power, or the like. The pads and wiring etc. for these purposes can be arranged in various ways. An example is described below.

[0123] FIG. 8 is a schematic plan view illustrating the wiring board 7 in region VIII in FIG. 2. In this figure, the chip 5, the drive IC 21, and the control IC 23 are also illustrated by dotted lines. For convenience of illustration, the number of wiring lines on the wiring board 7 may be illustrated to be significantly less than the actual number. In FIG. 8, only a portion of the wiring board 7 is illustrated. However, except for some parts (for example, a portion related to the control IC 23), the same configuration as illustrated in the figure is generally repeated on the -D1 side.

[0124] First, the paths from pads 69 to which the signal board 25 is connected to the pads 37 to which the chips 5 are connected (those pads to which a drive signal is input) will be described. Next, the paths from pads 83A, 83B, and 83C, to which the power boards 27 are connected, will be described.(2.7.1. Signal-related circuits)

[0125] The pads 69 to which the signal board 25 is connected are located substantially at an end portion of the wiring board 7 in the longitudinal direction. If the distance between the pads 69 and the short edge 7b is less than the length of the pads 69 in direction D1, the pads 69 may be considered to be located at the end portion of the wiring board 7. The number of pads 69 (two in FIG. 8) may correspond to the number of control signals input in parallel from the signal board 25 to the wiring board 7. In other words, the number of pads 69 may be any number equal to or greater than one.

[0126] Wiring lines 71 extending from the pads 69 are connected to some of multiple pads 73 to which terminals (not illustrated) of the control IC 23 are bonded. The wiring lines 71 are connected to the same number of pads 73 as the number of pads 69. The pads 73 to which the wiring lines 71 are connected are located closer to the pads 69 than the other pads 73. The control IC 23 and the pads 69 are arranged substantially side by side in the direction D1, and therefore the wiring lines extend substantially in the direction D1.

[0127] The pads 73 are arranged in two rows in the direction D2. Unlike in the illustrated example, some of the pads 73 may be located on the +D1 side and / or the -D1 side of the control IC 23. Wiring lines 75 extend from some of the pads 73 that are not connected to the pads 69.

[0128] The multiple wiring lines 75 transmit control signals distributed by the control IC 23 to the drive ICs 21. The number of wiring lines 75 is the same as the number of control signals output in parallel from the control IC 23, and is equal to or greater than the number of drive ICs 21. In FIG. 8, the same number (8) of wiring lines 75 as the number of drive ICs 21 is illustrated as an example.

[0129] The multiple wiring lines 75 are divided into those that extend toward the -D2 side and those that extend toward the +D2 side. Specifically, the wiring lines 75 extending from the pads 73 located on the -D2 side extend toward the -D2 side. The wiring lines 75 extending from the pads 73 located on the +D2 side extend toward the +D2 side.

[0130] The wiring lines 75 generally extend toward the corresponding long edge 7a and then extend along the long edge 7a toward the -D1 side (the side where the drive ICs 21 etc. are arranged). The wiring lines 75 also extend between the first row 29A (and the conversion circuit 67 on the -D2 side) and the long edge 7a on the -D2 side, or between the second row 29B (and the conversion circuit 67 on the +D2 side) and the long edge 7a on the +D2 side.

[0131] The multiple wiring lines 75 extending on the +D2 side correspond to the second row 29B and are connected to the conversion circuits 67 corresponding to the second row 29B. The multiple wiring lines 75 on the +D2 side are connected to the conversion circuits 67 in order starting from the wiring line 75 on the -D2 side, and extend toward the -D1 side as the number thereof decreases.

[0132] Similarly, the multiple wiring lines 75 extending on the -D2 side correspond to the first row 29A and are connected to the conversion circuits 67 corresponding to the first row 29A. The multiple wiring lines 75 on the -D2 side are connected to the conversion circuits 67 in order starting from the wiring line 75 the +D2 side, and extend toward the -D1 side as the number thereof decreases.

[0133] The conversion circuits 67 are located, for example, between the first row 29A and the long edge 7a on the -D2 side, or between the second row 29B and the long edge 7a on the +D2 side. The position of each conversion circuit 67 in the direction D1 is the same as the position, in the direction D1, of the corresponding drive IC 21 located on the same side in the direction D2 (for example, on the +D2 side for the conversion circuits 67 on the +D2 side). From another perspective, the arrangement ranges in the direction D1 of the conversion circuit 67 and the drive IC 21 on the same side in the direction D2 at least partially overlap each other. The length of the conversion circuit 67 in the direction D1 may be greater than the length of the drive IC 21 in the direction D1 (as in the illustrated example), or may be the same as or less than the length of the drive IC 21 in the direction D1.

[0134] Multiple wiring lines 77 (four in FIG. 8) extend from each conversion circuit 67 toward the center of the wiring board 7 in the width direction. The multiple wiring lines 77 transmit control signals input in parallel to the corresponding drive IC 21 by the conversion circuit 67. The number of wiring lines 77 extending from one conversion circuit 67 is the same as the number of control signals input in parallel to the drive IC 21, and is the same as the number of actuators 11 (nozzles 9) controlled by one drive IC 21. As mentioned above, this number may be, for example, 100 or more and 10,000 or less. For convenience, FIG. 8 illustrates only four wiring lines 77, which is an extremely small number.

[0135] The multiple wiring lines 77 are connected to some of the multiple pads 79 to which the drive IC 21 is bonded that are located on the outer side of the wiring board 7 in the width direction (on the side of the conversion circuit 67 to which the drive IC 21 is adjacent in the direction D2). The multiple wiring lines 77 extend substantially in the direction D2. Depending on the difference between the pitch of the connection positions between the conversion circuit 67 and the multiple wiring lines 77, and the pitch of the multiple pads 79, the multiple wiring lines 77 may extend at different angles to each other with respect to the direction D2 (see wiring lines 81 described later).

[0136] The pads 79 are arranged in two rows in the direction D2. Unlike in the illustrated example, some of the pads 79 may be located on the +D1 side and / or the -D1 side of the drive IC 21. Multiple wiring lines 81 extend from some of the pads 79 that are located on the opposite side in the direction D2 from the pads 79 connected to the conversion circuit 67.

[0137] The multiple wiring lines 81 transmit drive signals input from the drive IC 21 to the chip 5. The number of wiring lines 81 extending from one drive IC 21 is the same as the number of drive signals output in parallel from the drive IC 21 (from another perspective, the number of actuators 11 included in one chip 5). As is the case with the wiring lines 77, for convenience, an extremely small number of wiring lines 81, that is, four, is illustrated in FIG. 8.

[0138] The multiple wiring lines 81 are connected to some of the multiple pads 37 to which the chip 5 is bonded that are located around the center of the wiring board 7 in the width direction (the side of the drive IC 21 to which the chip 5 is adjacent in the direction D2). In the illustrated example, the pitch of the multiple pads 37 is greater than the pitch of the multiple pads 79. Therefore, the multiple wiring lines 81 extend at different angles inclined with respect to the direction D2. In other words, the multiple wiring lines 81 as a whole are arranged in a roughly trapezoid-shaped region. Of course, if the two pitches differ in another manner, the multiple wiring lines 81 may extend in a manner corresponding to that difference.

[0139] Depending on the amount of overlap between the ends of adjacent chips 5A and 5B, providing the wiring lines 81 connected to the ends of the chips 5 within the same plane may be difficult. In such a case, the wiring lines 81 may be provided so as to overlap each other with an insulating layer interposed therebetween.

[0140] FIG. 8 illustrates pads 79 and 37 as dummy pads that are not connected to any circuits and are only used to balance the connections. However such dummy pads do not need to be provided.(2.7.2. Power-related circuits)

[0141] Among the pads 83A and 83B, one is supplied with a reference potential from the corresponding power board 27, and the other is supplied with a power supply potential from the corresponding power board 27. The pads 83A and 83B contribute to supplying power to the drive IC 21 and the conversion circuit 67. The pad 83C is supplied with a reference potential from the power board 27. The pad 83C contributes to supplying a reference potential to the chip 5 (more specifically, the lower electrode 55).

[0142] In FIG. 8, illustration of the paths from the pads 83A to 83C to the control IC 23 is omitted. Illustration of the pads 73 related to these paths is also omitted. These paths are arbitrary. For example, a wiring line that applies a reference potential from the pad 83C closest to +D1 side to the pad 73 and a wiring line that applies a power supply potential from the pad 83B closest to +D1 side to pad 73 may be provided.

[0143] The pads 83A and 83B are located roughly on the edge portion on the long edge 7a side of the wiring board 7. For example, so long as the distance between the pads 83A and 83B and the long edge 7a is smaller than the length of the pads 83A and 83B in the direction D2, the pads 83A and 83B may be considered as being located on the edge portion of the wiring board 7. From another perspective, the pads 83A and 83B are located on the long edge 7a side with respect to the multiple wiring lines 75 extending along one long edge 7a.

[0144] The multiple wiring lines 75 extending along the long edge 7a are locally shifted toward the inside of the wiring board 7 to avoid the positions of the pads 83A and 83B located at the edge portion of the wiring board 7. However, with respect to the pad 83A closest to the -D1 side, the multiple wiring lines 75 do not need to be shifted inward to avoid the pad 83A because their ends are located in front of the pad 83A (on the +D1 side). In addition, the multiple wiring lines 75 may pass below the pads 83A and 83B with an insulating film interposed therebetween.

[0145] The pads 83A and 83B are each provided in the same number as the number of drive ICs 21, for example. On each of the -D2 side and +D2 side, the pad 83A is located on the -D1 side of each drive IC 21, and the pad 83B is located on the +D2 side of each drive IC 21. From another perspective, the same number of pads 83A (pads 83B) as the number of drive ICs 21 are arranged at the same pitch as the pitch of the drive ICs 21. Unlike in the above description, the multiple pads 83A (multiple pads 83B) may be arranged at a constant pitch, with one more or one less than the number of drive ICs 21.

[0146] The pads 83A and 83B supply power to, for example, the nearest one of the multiple conversion circuits 67 and the multiple drive ICs 21. FIG. 8 illustrates an embodiment in which power is supplied to one drive IC 21 (and the corresponding conversion circuit 67) from the pads 83A and 83B located on both sides of the drive IC 21. That is, two wiring lines 85 extend from the pads 83A and 83B on both sides of one drive IC 21 and connect to two pads 79 and the conversion circuit 67. The paths of the wiring lines 85 are arbitrary. In FIG. 8, the wiring lines 85 extend so as to cross the wiring lines 75 with an insulating layer (not illustrated) interposed therebetween. Either of the wiring lines 75 and 85 may be located above the other.

[0147] The pad 83C is located between the chip 5 located on the same side in the direction D2 and the long edge 7a, and further between the chip 5 located on the same side in the direction D2 and multiple wiring lines 75. The pad 83C applies a reference potential to the chip 5 adjacent thereto in the direction D2. More specifically, one or more wiring lines 87 (two in FIG. 8) extend from one pad 83C. The wiring lines 87 are connected to the pads 37 located on the pad 83C side in the direction D2, among the multiple pads 37.

[0148] On each of the -D2 side and the +D2 side, the number of pads 83C is, for example, the same as the number of chips 5. The position of each pad 83C in the direction D1 is, for example, located at the center of the corresponding chip 5 in the direction D1. From another perspective, the multiple pads 83C are arranged at the same pitch as the pitch of the multiple chips 5.

[0149] The shape, extending direction, etc. of the multiple wiring lines 87 are arbitrary. Unlike in the illustrated example, the wiring lines 87 do not need to have a linear shape. For example, the wiring lines 87 may extend toward the chip 5 (in the direction D2) with a width in the direction D1 that is the same as the length of the pad 83C in the direction D1, or the width (in the direction D1) may be greater than the length in the direction D2.

[0150] The arrangement of the pads 83A to 83C described above is repeated toward the -D1 side of the range illustrated in FIG. 8. Therefore, although not specifically illustrated, the pads 83B, 83C, and 83A are arrayed in order from the -D1 side at equal intervals between each chip 5 and the adjacent long edge 7a, except for the chip 5 (5B) closest to the -D1 side and the chip 5 (5A) closest to the +D1 side. At these positions, the multiple wiring lines 75 bend toward the inside of the wiring board 7 on both sides of the pad 83C in the direction D1 to avoid the pads 83B and 83A.

[0151] The power board 27 includes, for example, three types of terminals that are individually bonded to the three types of pads 83A to 83C. However, the power board 27 may also include a terminal that is bonded to both the pad 83A or 83B to which the reference potential is applied and the pad 83C.(3. Other examples)

[0152] Below, examples different from the examples described thus far will be described. In the following description, basically, only differences from the examples described earlier will be described. Matters not specifically mentioned may be considered to be the same as or similar to the examples described earlier or may be inferred from the examples described earlier. For convenience, hereinafter, corresponding components in different examples may be denoted by the same reference symbols even if there are differences.(3.1. Other examples of drive ICs)

[0153] FIG. 9 is a cross-sectional view illustrating another example of a drive IC, and corresponds to FIG. 4.

[0154] In the head 3 in FIG. 4, the drive IC 21 is an electronic component mounted on the wiring board 7. On the other hand, in a head 203 in FIG. 9, a drive IC 221 is included in a wiring board 207. More specifically, the drive IC 221 is built into the wiring board 207. Such a drive IC 221 may be configured, for example, by an LTPS circuit included in an LTPS substrate serving as the wiring board 207.

[0155] The shape and size of the drive IC 221 may be the same as or similar to or different from the shape and dimensions of the drive IC 21. The example in FIG. 9 illustrates an embodiment in which the upper surface of the drive IC 221 is lower than the upper surface of the drive IC 21, and therefore lower than the upper surface of the chip 5. On the other hand, the dimension of the drive IC 221 in the direction D2 (and / or the direction D1, not specifically illustrated) is larger than that of the drive IC 21. For example, the length of the drive IC 221 in the direction D2 is greater than the length of the opening 31 in the direction D2 (and also the length of the chip 5 in the direction D2).

[0156] The drive IC 221 does not include terminals (see terminals 21a in FIG. 4) to be bonded to the wiring board 207, and the signal input sections are conductors of the wiring board 207. The conversion circuit 67 may be provided in a manner so as to be distinguishable from the drive IC 221, or may be provided in a manner so as not to be distinguishable from the drive IC 221. Although not particularly illustrated, the control IC may also be included in the wiring board 207 (for example, an LTPS circuit) the same as or similarly to the drive IC 221. In other words, the drive IC and / or the control IC may be included in the wiring board.(3.2. Other examples of flexible boards)(3.2.1. First Example)

[0157] FIG. 10 is a diagram illustrating another example of power boards, and corresponds to FIG. 2.

[0158] In the head 3 in FIG. 4, the power boards 27 extend outward from the wiring board 7 on only one side in the longitudinal direction, and are provided with external connection portions 27a. On the other hand, in a head 303 in FIG. 10, the power boards 27 extend outward from the wiring board 7 on both sides in the longitudinal direction, and are provided with external connection portions 27a. For example, both the reference potential and the power supply potential (or the power supply potential) are applied to the power boards 27 at each connection portion 27a.

[0159] In the head 303, the distance between the connection portions 27a and the pads 83A to 83C (FIG. 8) farthest from connection portions 27a is roughly half that in the head 3. Furthermore, the width of the wiring lines inside the power board 27 can be doubled. As a result, for example, the likelihood of the power supply potential affecting the power boards 27 is reduced. Furthermore, the head 3 is advantageous in terms of size reduction compared to the head 303, because the power boards 27 are led out to only one side in the longitudinal direction.(3.2.2. Second Example)

[0160] FIG. 11 is a diagram illustrating another example of the power boards, and corresponds to FIG. 2.

[0161] In the head 3 in FIG. 2, the power board 27 is contained between the first row 29A (or the second row 29B) and the long edge 7a adjacent to the first row 29A. On the other hand, in a head 403 in FIG. 11, power boards 427 protrude outward beyond the long edges 7a (not illustrated in FIG. 11 as hidden by the power boards 427). This is described in more detail below, for example.

[0162] Let us suppose that the power board 427 is not bent and is arranged flat parallel to the wiring board 7 (see power board 427A on the -D2 side). In this case, the power board 427 includes an extending portion 427e including a part extending along the long edge 7a outside the long edge 7a, and multiple branch portions 427f extending from the extending portion 427e toward the inside from the long edge 7a and connected to the pads 83A to 83C (FIG. 8). The entirety of the extending portion 427e may be located outside the long edge 7a (including a case in which the inner edge coincides with the long edge 7a), or a portion may be located inside the long edge 7a. For example, at least one half or two thirds of the width (in the direction D2) of the extending portion 427e may be located outside the long edge 7a.

[0163] As illustrated by a power board 427B on the -D2 side, the power board 427 may be used with the extending portion 427e bent relative to the branch portions 427f (of course, power board 427 may be used without being bent). In this case, the power board 427 may be bent, for example, so that the extending portion 427e is aligned with the direction D3, or so that extending portion 427e overlaps the wiring board 7, and may be configured to not protrude from the long edge 7a in plan view of the wiring board 7, or may protrude from the long edge 7a. The power board 427 may be maintained in a bent state by another member (for example, a flow path member, heat sink, or housing described above) abutting the extending portion 427e.

[0164] The positions of the branch portions 427f correspond to the positions of the pads 83A to 83C. As described with reference to FIG. 8, for example, three pads 83A to 83C (or two pads) are arrayed at the center of each chip 5 in the direction D1. In FIG. 8, an example is illustrated in which the branch portion 427f is commonly provided for the three pads 83A to 83C. Although not specifically illustrated, when a pad 83A or 83B that is not adjacent to a chip 5 exists, a branch portion 427f for that pad may of course be provided. Furthermore, the branch portion 427f may not be provided in common to the three (or two) pads, but rather may be provided individually for each pad.

[0165] The shapes and dimensions etc. of the branch portions 427f are arbitrary. For example, when the power board 427 is arranged flat, the end of each branch portion 427f at the side of the extending portion 427e (from another perspective, the edge of the extending portion 427e at the side of the branch portion 427f) may be located inside the long edge 7a, on the long edge 7a (in the illustrated example), or outside the long edge 7a. Furthermore, for example, the planar shape of the branch portion 427f may be rectangular (in the illustrated example) or trapezoidal.

[0166] In FIG. 11, the power board 427 has external connection portions 427a on both sides in the longitudinal direction, similarly to the example in FIG. 10. Unlike in the illustrated example, the power board 427 may have the connection portion 427a only on the -D1 side or +D1 side. Furthermore, although not specifically illustrated, when the power board 427 includes a part extending outward from the long edge 7a, the power board 427 may include no branch portions 427f. In other words, the power board 427 may simply be a power board 27 that is wider in an outward direction from the long edge 7a.(3.2.3. Third Example)

[0167] FIG. 12 is a diagram illustrating another example of the power boards, and corresponds to FIG. 2.

[0168] In the head 3 in FIG. 2, each power board 27 extends along the corresponding long edge 7a and is connected to the multiple pads 83A to 83C (FIG. 8) arranged along the long edge 7a. On the other hand, in a head 503 in FIG. 12, multiple power boards 527 are arranged along the long edges 7a and are connected to the multiple pads 83A to 83C arranged along the long edges 7a.

[0169] From another perspective, the power boards 527 can be regarded as being configured by removing the extending portions 427e from the power boards 427 in FIG. 11 and allowing the branch portions 427f to serve as the power boards 527. Therefore, the description of the branch portions 427f (for example, that the branch portions 427f are provided to correspond to the positions of the pads 83A to 83C) may be applied to power board 527 as long as no contradictions etc. arise.

[0170] For example, when the power boards 527 are not bent and are arranged flat parallel to the wiring board 7, the power boards extend outward from the connection positions to the wiring board 7 along the long edges 7a. From another perspective, the part (end portion) of each power board 527 located on the -D2 side or +D2 side relative to the joining position to the wiring board 7 forms a connection portion 527a that is connected to another component on the side where the controller 19 is located.

[0171] Similarly to each power board 427, each power board 527 may be used with the portion extending outward from the long edge 7a bent relative to the portion joined to the wiring board 7 (although, of course, may also be used without being bent). Regarding this, the description of the power boards 427 may be applied to the power boards 527.(3.2.4. Fourth example)

[0172] FIG. 13 is a perspective view illustrating another example of power boards. In the figure, a unit 613 including heads 603 (four in the illustrated example) is illustrated, similarly to FIG. 1.

[0173] In each head 603, the power boards 27 extend out from the same side as the signal board 25, unlike in the head 3. The power boards 27 and the signal board 25 are connected to the same control board 33. Furthermore, the multiple heads 603 are connected to the same control board 33.

[0174] As indicated by the two-dot chain line, the power boards 27 and the signal boards 25 may be used in a bent state where the control board 33 overlaps the wiring board 7 (of course, may also be used without being bent). In this case, the control board 33 may be in contact with the wiring board 7 and an assembly including electronic elements mounted on the wiring board 7, or may be separated by being supported by another member. In a planar perspective view, the control board 33 may be contained within the arrangement area of multiple (four) wiring boards 7 (in the illustrated example), or may protrude on the +D1 side, -D2 side, and / or +D2 side. This similarly applies to the power boards 27 and the signal boards 25. Unlike in the illustrated example, the power boards 27 and the signal boards 25 may be bent so that the control board 33 extends along the direction D3.(3.3. Other matters)

[0175] In the example in FIG. 4, the chip 5 is mounted on the upper surface (+D3 side) of the wiring board 7. From another perspective, the direction in which the chip 5 is bonded to the wiring board 7 (towards the -D3 side) is the same as the direction in which the nozzles 9 open (towards the -D3 side). Conversely, the chip 5 may be mounted on the lower surface of the wiring board. From another perspective, the direction in which the chip 5 is bonded to the wiring board 7 may be opposite to the direction in which the nozzles 9 open.

[0176] For example, although not specifically illustrated, a wiring board including a conductor layer on the lower surface thereof (-D3 side) may be used as the wiring board 7. Furthermore, in the configuration in FIG. 7, the relay substrate 45 may be eliminated. Then, the through conductors 43b of the support substrate 43 are used as terminals of the chip 5 and are bonded to the pads 37 located on the lower surface of the wiring board 7. A protruding portion of the flow path member is inserted into the opening 31 of the wiring board 7 from the +D3 side, and ink is supplied from the protruding portion to the common flow path 47 that opens on the upper surface of the relay substrate 45.

[0177] In the configuration in FIG. 7, the edges of the relay substrate 45 on the -D2 side and the +D2 side may be removed in order to expose the through conductors 43b, and the through conductors 43b may be bonded to the pads 37 on the lower surface of the wiring board 7. The relay substrate 45 may be inserted into the opening 31 of the wiring board 7.(4. Summary of embodiments)

[0178] In the following, specific configurations of the embodiments will be extracted and their functions and effects will be illustrated. In the following description, for convenience, the reference symbols in FIGs. 1 to 8 will be primarily used. However, the following description also applies to the examples in FIGs. 9 to 13 unless there are any contradictions etc.

[0179] A liquid ejection head (head 3) includes the chips 5 and the rigid wiring board 7. Each chip 5 includes the nozzles 9 and the actuators 11 for ejecting liquid from the nozzles 9. The wiring board 7 supports the chips 5 and is electrically connected to the chips 5 (i.e., the chips 5 are mounted on the wiring board 7).

[0180] Therefore, as described in the description of the outline of the embodiments, the wiring board 7 functions as a component that serves as both the flexible board and the frame in the comparative example (see the BACKGROUND OF INVENTION section). In other words, the number of parts is reduced. As a result, for example, reductions in cost and / or size are expected.

[0181] The head 3 may include multiple chips 5 supported by the same wiring board 7.

[0182] In this case, for example, the head 3 that is realized can perform band-shaped printing over a range longer than the length (direction D1) of each chip 5. For example, as illustrated in FIGs. 2 and 3, a line head that can print across the width of the paper is realized by chips 5 that are shorter than the width of the paper. As a result, for example, compared to an embodiment in which a long chip that spans the width of the paper (such an embodiment may also be included in a technology according to the present disclosure), improving the dimensional accuracy of the flow path shape, etc., and improving the strength of the entire head are easier.

[0183] The chips 5 may be MEMS chips. The wiring board 7 may be an LTPS substrate.

[0184] In this case, for example, because each chip 5 is MEMS chips, the nozzles 9, actuators 11, terminals 35, etc. can be formed with high density and precision through microfabrication. Furthermore, for example, because the wiring board 7 is an LTPS substrate, the pads 37, etc. connected to the terminals 35 can be formed with high density and precision through microfabrication. Therefore, when the nozzles 9, terminals 35, etc. are densified in order to reduce the size of the chip 5, the likelihood of limitations imposed by the dimensional precision of the wiring board 7 is reduced. The reverse is also true in that the likelihood of the miniaturization of the wiring board 7 being limited by the dimensional precision of the chip 5 is reduced. Furthermore, when a circuit (e.g., the conversion circuit 67) is formed on the wiring board 7, the circuit can be miniaturized if the wiring board 7 is an LTPS substrate. These factors contribute to the size reduction of the head 3.

[0185] The head 3 may further include (at least one) drive IC 21 that drives the actuators 11. The drive IC 21 may be mounted on the wiring board 7 or may be included in the wiring board 7.

[0186] In this case, for example, the wiring board 7 not only contributes to the transmission of signals to the actuators 11 but also contributes to the placement of the drive IC 21. As a result, the number of components is further reduced compared to, for example, an embodiment in which the drive IC 21 is mounted on a flexible board connected to the wiring board 7 (this embodiment may also be included in a technology according to the present disclosure). As a result, for example, reductions in cost and / or size are expected.

[0187] The drive IC 221 (FIG. 9) may be configured by an LTPS circuit of the wiring board 207.

[0188] In this case, for example, a process of fabricating the drive IC 21 separately from the wiring board 7 and mounting the drive IC 21 on the wiring board 7 is not required. As a result, for example, cost reductions are expected. Furthermore, the strength required for the drive IC 21 as a chip does not need to be ensured for the drive IC 221 as an LTPS circuit, and so the drive IC 221 can be made thinner. Consequently, a reduction in the thickness of the head 3 is expected.

[0189] In a plan view of the wiring board 7 (or, from another perspective, when viewed in the opening direction of the nozzles 9), the multiple chips 5 may be arranged in a staggered pattern. Each drive IC 21 may be located between adjacent chips 5. In this case, as described above, the number of chips 5 may be three or more.

[0190] When implementing a head 3 capable of printing over a range longer than the length of each chip 5 (in the direction D1) by using multiple chips 5, if there is only one row of chips 5, there will be areas between adjacent chips 5 where printing does not occur. For this reason, multiple chips 5 are arranged in two or more rows in a staggered pattern, with their ends in the direction D1 overlapping. In this case, the staggered arrangement creates dead space on the wiring board 7 where no chips 5 are located. This dead space can be utilized as locations in which to arrange the drive ICs 21. As a result, the head 3 can be reduced in size. This is made possible by using the wiring board 7 as a member that supports the multiple chips 5, and is a configuration that would not be possible with the configuration of the comparative example described in the BACKGROUND OF INVENTION.

[0191] In a plan view of the wiring board 7, multiple chips may be arranged in a staggered pattern in two rows. In a plan view of the wiring board 7, multiple drive ICs 21 (for example, the same number as the number of chips 21) may be arranged in a staggered pattern in two rows so as to be positioned between multiple chips 5.

[0192] In this case, the dead space can be more effectively utilized. Furthermore, since the multiple chips 5 and the multiple drive ICs 21 are adjacent to each other, the configuration of the wiring lines 81 and the like of the wiring board 7 for connecting the chips 5 and the drive ICs 21 can be simplified. As a result, for example, reducing the size of the wiring board 7 in plan view is facilitated.

[0193] In an embodiment in which multiple chips 5 and multiple drive ICs 21 are disposed in a staggered pattern, the wiring board 7 may connect the chips 5 and drive ICs 21 that are adjacent to each other in a direction (direction D2) that intersects the row of the multiple chips 5 (first row 29A or second row 29B).

[0194] In this case, for example, associating one chip 5 with one drive IC 21 is easy, and the effect of simplifying the wiring lines 81 etc. is improved. Furthermore, since the multiple chips 5 are arranged in the longitudinal direction of each chip and there is a high probability that each chip has a terminal 35 on the -D2 side or the +D2 side, the effect of simplifying the wiring lines 81 etc. is also improved from this point of view.

[0195] In plan view, the wiring board 7 may have a first long edge and a second long edge (the long edge 7a on the -D2 side and a long edge on the +D2 side) extending parallel to each other in the longitudinal direction (direction D1) of the wiring board 7. The multiple chips 5 and the multiple drive ICs 21 may be arranged along the direction D1 and form the first row 29A on the -D2 side and the second row 29B on the +D2 side. The wiring board 7 may include a first circuit (conversion circuit 67 on the -D2 side). The conversion circuits 67 on the -D2 side may be located between the first row 29A and the long edge 7a on the -D2 side and may input signals to the multiple drive ICs 21 in the first row 29A.

[0196] In this case, for example, first, because the conversion circuits 67 are built into the wiring board 7, the size or number of parts is expected to be reduced compared to an embodiment in which the conversion circuits 67 are provided on another circuit board (this embodiment may also be included in a technology according to the present disclosure). Furthermore, because the conversion circuit 67 is provided for each drive IC 21, the configuration of the wiring board 7 is simplified compared to an embodiment in which conversion circuits 67 corresponding to multiple drive ICs 21 are provided at the end of the wiring board 7 in the direction D1 (this embodiment may also be included in a technology according to the present disclosure).

[0197] The first circuit (conversion circuit 67 on the -D2 side) may include a serial-parallel conversion circuit that distributes a signal supplied to the drive IC 21 to multiple input sections (terminals 21a) of the drive IC 21.

[0198] In this case, for example, the number of wiring lines 81 after the conversion circuit 67 (on the drive IC 21 side) is greater than the number of wiring lines 75 before the conversion circuit 67 (on the control IC 23 side). Therefore, compared to an embodiment in which conversion circuits 67 corresponding to multiple drive ICs 21 are provided at the end of the wiring board 7 in the direction D1, the area required for the multiple wiring lines 75 and the multiple wiring lines 81 can be reduced. As a result, the wiring board 7 is made smaller in size in plan view.

[0199] The head 3 may further include the control IC 23 that inputs signals to the multiple drive ICs 21 via the first circuit (conversion circuit 67 on the -D2 side). The control IC 23 may be mounted on the wiring board 7 at a position on the first side (+D1 side) in the longitudinal direction (direction D1) of the wiring board 7 relative to the first row 29A, or may be included in the wiring board 7.

[0200] In this case, first, because the control IC 23 is provided on the wiring board 7, the head 3 is expected to be smaller in size than in an embodiment in which the control IC 23 is provided on another board connected to the wiring board 7 (this embodiment may also be included in a technology of the present disclosure). Furthermore, although connections to external elements (signal board 25) for the wiring board 7 are concentrated at one end of the wiring board 7, the area required for the multiple wiring lines 75 and the multiple wiring lines 81 can be reduced by providing the conversion circuits 67 for the drive ICs 21, as described above. As a result, the signal board 25 and the wiring board 7 as a whole can be made smaller in size than in an embodiment in which external elements (corresponding to the signal board 25) are directly connected to the conversion circuits 67 (this embodiment may also be included in a technology of the present disclosure). Furthermore, the wiring board 7 can be made thinner than in an embodiment in which the control IC 23 is located closer to the long edge 7a than the conversion circuit 67 (this embodiment may also be included in a technology of the present disclosure). As a result, for example, arranging multiple heads 3 in a narrow range in the direction D2 is facilitated. This in turn results in an improved degree of freedom in the configuration of the transport device 17, for example.

[0201] The head 3 may further include a flexible board (signal board 25) that inputs a signal to the control IC 22 via the wiring board 7. The signal board 25 may be connected to the wiring board 7 at a connection position on the first side (+D1 side) of the control IC 23, and may include the connection portion 25a for connection to the outside in a portion extending from the connection position toward the first side when the signal board 25 is not bent and is arranged flat parallel to the wiring board 7.

[0202] In this case, for example, the effect of facilitating arranging multiple heads 3 in a narrow range in the direction D2 is improved.

[0203] The head 3 may further include a flexible board (power board 27A) that applies a first potential (power supply potential or reference potential) to the multiple drive ICs 21. The wiring board 7 may have a first long edge and a second long edge (long edge 7a on the -D2 side and long edge 7a on the +D2 side) that extend parallel to each other in the longitudinal direction (direction D1) of the wiring board 7 in plan view. The multiple chips 5 and the multiple drive ICs 21 may be arranged along the direction D1 and form the first row 29A on the -D2 side and the second row 29B on the +D2 side. When the power board 27A is not bent and is arranged flat parallel to the wiring board 7, the power board 27A may extend along the long edge 7a on the -D2 side, and may be connected to the wiring board 7 at multiple first positions in the direction D1 between the first row 29A and the long edge 7a on the -D2 side (for example, multiple pads 83A (or 83B or 83C) on the -D2 side) for applying a first potential, and may include the connection portion 27a to which a first potential is applied from the outside in a portion extending outward in the direction D1 (to the -D1 side and / or +D1 side) beyond all of the first positions (and / or the first row 29A, and furthermore the wiring board 7).

[0204] In this case, the power board 27 extends outward in the longitudinal direction of the wiring board 7. This facilitates making the head 3 including the power board 27 thinner (reducing the size in the direction D2) than in an embodiment in which the power board 27 extends outward in the lateral direction of the wiring board 7 (e.g., the example in FIG. 12). As a result, for example, arranging multiple heads 3 in a narrow range in the direction D2 is facilitated. On the other hand, if the power board 27 is simply located at the end of the wiring board 7 in the longitudinal direction like in the case of the signal board 25 (such an embodiment may also be included in a technology according to the present disclosure), there is a possibility that the power supply potential supplied to the drive ICs 21 far from the power board 27 will drop if the wiring resistance of the wiring board 7 is high (e.g., if the wiring board 7 is an LTPS substrate with thin wiring). However, by making the power board 27 extend along the long edge 7a and be connected to the wiring board 7 at multiple positions, the likelihood of such a problem is reduced.

[0205] In the above configuration, when the power board 27A is not bent and is arranged flat parallel to the wiring board 7, the power board 27A may extend along the first long edge (long edge 7a on the -D2 side) inside the first long edge when viewed in perspective plan view.

[0206] In this case, for example, the effect of making the head 3 including the power board 27 thinner (reducing the size in the direction D2) is improved.

[0207] Unlike in the above description, as illustrated in FIG. 11, when the power board 427A is not bent and is arranged flat parallel to the wiring board 7, the power board 427A may include the extending portion 427e that extends along the first long edge (the long edge 7a on the -D2 side) outside the first long edge, and multiple branch portions 427f that extend from the extending portion 427e toward the inside from the first long edge and are connected to multiple first positions (each first position is connected to at least one of the pads 83A to 83C on the -D2 side).

[0208] In this case, for example, compared to an embodiment using a power board 27 that fits inside the long edge 7a, the wiring width can be increased, thereby reducing wiring resistance. As a result, for example, the likelihood of a voltage drop can be reduced.

[0209] The head 503 (FIG. 12) may include flexible boards (power boards 527) that supply power to the multiple drive ICs 21. The wiring board 7 may have a first long edge and a second long edge (a long edge 7a on the -D2 side and a long edge 7a on the +D2 side) that extend parallel to each other in the longitudinal direction (direction D1) of the wiring board 7 in plan view. The multiple chips 5 and the multiple drive ICs 21 may be arranged along the direction D1 and form the first row 29A on the -D2 side and the second row 29B on the +D2 side. The multiple power boards 527 on the -D2 side may be arranged along the long edge 7a on the -D2 side and connected to the wiring board 7 between the first row 29A and the long edge 7a on the -D2 side.

[0210] In this case, increasing the width of the wiring and reducing the wiring resistance becomes easier compared to an embodiment including a power board 27 (or 427) that extends along the long edge 7a. Note that an embodiment including a long power board 27 allows the number of external connection parts 27a to be reduced compared to an embodiment including multiple power boards 527, which is advantageous for making the head 3 smaller.

[0211] In an embodiment in which the signal board 25 is located on the first side (+D1 side) in the longitudinal direction of the wiring board 7, each head 603 (FIG. 13) may further include a flexible board (power board 27A) that supplies power to the drive ICs 21. The power board 27A may extend along the first long edge (long edge 7a on the -D2 side) and may be connected to the wiring board 7 at multiple positions in the direction D1 between the first row 29A and the long edge 7a on the -D2 side, and may include external connection portions 25a in a portion extending toward the first side (+D1 side) beyond the above-mentioned multiple positions (and / or the first row 29A and also beyond the short edge 7b of the wiring board 7).

[0212] In this case, for example, the signal board 25 and the power board 27 can be connected to the same control board 33 on the first side (+D1 side). That is, the number of parts can be reduced. As a result, for example, a reduction in cost is expected. Note that in an embodiment in which the signal board 25 and the power boards 27 are led out on opposite sides (FIG. 2), for example, making each of the two boards individually connected to the signal board 25 and the power board 27 smaller or more multifunctional is facilitated.

[0213] As illustrated in FIG. 13, the liquid ejection unit (unit 613) may include liquid ejection heads (heads 603) and a rigid substrate (control board 33) electrically connected to the heads 603. The multiple heads 603 may be arranged in the lateral direction of the wiring board 7. Each of the multiple heads 603 may include a flexible board (signal board 25 and / or power board 27) connected to the wiring board 7. Portions (connection portions 25a and / or 27a) of the multiple flexible boards located on the first side (+D1 side) in the longitudinal direction of the wiring board 7 with respect to the connection positions to the wiring board 7 may be connected to the same control board 33, and the control board 33 may be folded back so as to overlap the multiple wiring boards 7.

[0214] In this case, for example, the effect of reducing the number of components can be achieved, and the area of the unit 613 in plan view can be reduced. As a result, the printer 1 including the unit 613 can be reduced in size.

[0215] A technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0216] The recording device may be a plotter. The recording device may be a handheld printer that is held and moved entirely by a user and moves relative to a recording medium. The recording device may also be a device that moves the recording medium and the head relative to each other by moving the head using a robot or the like (a robot is an example of a transport device).

[0217] The recording medium is not limited to paper. The recording medium may be, for example, cloth, wood, tile, a printed wiring board (more specifically, an insulating layer on which a conductive pattern is printed), or a car body.

[0218] The head may be used for purposes other than recording devices. For example, the head may be used in the manufacture of chemicals. Specifically, for example, the head may eject a predetermined amount of a liquid chemical or a liquid containing a chemical toward a reaction vessel or the like.

[0219] As can be understood from the examples of the recording medium and the like given above, the liquid is not limited to ink. For example, the liquid may be paint or a conductive material to be printed on a printed wiring board.REFERENCE SIGNS

[0220] 1printer (recording device), 3head (liquid ejection head), 5chip, 7wiring board, 9nozzle, 11actuator, 13unit (liquid ejection unit).

Claims

1. A liquid ejection head comprising: a chip including a nozzle and an actuator configured to eject liquid from the nozzle; and a rigid wiring board configured to support the chip and electrically connected to the chip.

2. The liquid ejection head according to claim 1, wherein a plurality of the chips is supported on the same wiring board.

3. The liquid ejection head according to claim 1 or 2, wherein the chip is a MEMS chip, and the wiring board is an LTPS substrate.

4. The liquid ejection head according to any one of claims 1 to 3, further comprising: a drive IC configured to drive the actuator, wherein the drive IC is mounted on the wiring board or is included in the wiring board.

5. The liquid ejection head according to claim 4, wherein the drive IC is configured by an LTPS circuit of the wiring board.

6. The liquid ejection head according to claim 4 or 5, wherein in a plan view of the wiring board, the plurality of chips is arranged in a staggered pattern, and the drive IC is located between adjacent chips among the plurality of chips.

7. The liquid ejection head according to claim 6, wherein in a plan view of the wiring board, the plurality of chips is arranged in a staggered pattern in two rows, and in a plan view of the wiring board, the plurality of drive ICs is arranged in a staggered pattern in two rows and positioned between the plurality of chips.

8. The liquid ejection head according to claim 7, wherein the wiring board connects the chips and the drive ICs that are adjacent to each other in a direction intersecting the rows of the plurality of chips.

9. The liquid ejection head according to claim 7 or 8, wherein the wiring board has a first long edge and a second long edge extending parallel to each other in a longitudinal direction of the wiring board in plan view, the plurality of chips and the plurality of drive ICs are arranged along the longitudinal direction and form a first row on a side near the first long edge and a second row on a side near the second long edge, and the wiring board includes a first circuit that is located between the first row and the first long edge and inputs signals to the plurality of drive ICs in the first row.

10. The liquid ejection head according to claim 9, wherein the first circuit includes a serial-parallel conversion circuit that distributes a signal supplied to each of the drive ICs to a plurality of input sections of the drive IC.

11. The liquid ejection head according to claim 9 or 10, further comprising: a control IC configured to input signals to the plurality of drive ICs via the first circuit, wherein the control IC is mounted on the wiring board or included in the wiring board at a position further toward a first side in the longitudinal direction of the wiring board than the first row.

12. The liquid ejection head according to claim 11, further comprising: a signal board configured as a flexible board and configured to input signals to the control IC via the wiring board, wherein the signal board is connected to the wiring board at a connection position further toward the first side than the control IC, and includes a connection portion for external connection in a portion extending from the connection position toward the first side when the signal board is not bent and is arranged flat parallel to the wiring board.

13. The liquid ejection head according to any one of claims 7 to 12, further comprising: a power board configured as a flexible board and configured to supply a first potential to the plurality of drive ICs, wherein the wiring board has a first long edge and a second long edge extending parallel to each other in a longitudinal direction of the wiring board in plan view, the plurality of chips and the plurality of drive ICs are arranged along the longitudinal direction and form a first row on a side near the first long edge and a second row on a side near the second long edge, and when the power board is not bent and is arranged flat parallel to the wiring board, the power board extends along the first long edge and applies the first potential to the wiring board while connected to the wiring board between the first row and the first long edge at a plurality of first positions in the longitudinal direction, and includes a connection portion, to which the first potential is externally applied, in a portion thereof extending outward in the longitudinal direction beyond the plurality of first positions.

14. The liquid ejection head according to claim 13, wherein when the power board is not bent and is arranged flat parallel to the wiring board, the power board extends along the first long edge without protruding outside the wiring board from the first long edge in a planar perspective view.

15. The liquid ejection head according to claim 13, wherein when the first board is not bent and is arranged flat parallel to the wiring board, the first board includes an extending portion that extends along the first long edge outside the first long edge, and a plurality of branch portions extending from the extending portion inward relative to the first long edge and connected to the plurality of first positions.

16. The liquid ejection head according to any one of claims 7 to 12, further comprising: a power board configured as a flexible board and configured to supply power to the plurality of drive ICs, wherein the wiring board has a first long edge and a second long edge extending parallel to each other in a longitudinal direction of the wiring board in plan view, the plurality of chips and the plurality of drive ICs are arranged along the longitudinal direction and form a first row on a side near the first long edge and a second row on a side near the second long edge, and a plurality of the power boards are arranged along the first long edge and connected to the wiring board between the first row and the first long edge.

17. The liquid ejection head according to claim 12, further comprising: a power board configured as a flexible board and configured to supply power to the plurality of drive ICs, wherein the power board extends along the first long edge, is connected to the wiring board between the first row and the first long edge at a plurality of positions in the longitudinal direction, and includes an external connection portion in a portion thereof extending toward the first side beyond the plurality of positions.

18. A liquid ejection unit comprising: the liquid ejection head according to any one of claims 1 to 17; and a control board configured as a rigid board and electrically connected to the liquid ejection head, wherein a plurality of the liquid ejection heads is arranged in a lateral direction of the wiring board, each of the plurality of liquid ejection heads includes a flexible board connected to the wiring board, and the multiple flexible boards are connected to the same control board at portions of the flexible boards located further toward a first side in the longitudinal direction of the wiring board than connection positions of the flexible boards to the wiring board, and the control board is folded back and overlaps the wiring board.

19. A recording device comprising: the liquid ejection head according to any one of claims 1 to 17; and a transport device configured to move the liquid ejection head relative to a recording medium on which liquid ejected from the nozzle lands.

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