Liquid discharge head, liquid discharge unit, and recording device

Abstract

A liquid discharge head (3) comprises a chip (5) and a rigid wiring board (7). The chip (5) has a nozzle and an actuator for discharging a liquid from said nozzle. The wiring board (7) supports the chip (5) and is electrically connected with the chip (5).

Description

Liquid ejection head, liquid ejection unit and recording apparatus

[0001] The present disclosure relates to a liquid ejection head such as an inkjet head, a liquid ejection unit having the liquid ejection head, and a recording apparatus having the liquid ejection head.

[0002] Liquid ejection heads (e.g., inkjet heads) that eject liquid (e.g., ink) toward a recording medium (e.g., paper) are known (see, for example, Patent Document 1 below). Such heads include, for example, a head body and a flexible substrate connected to the head body. The head body includes nozzles and actuators that eject liquid (e.g., droplets) from the nozzles. The flexible substrate contributes to electrically connecting, for example, the actuator to a driving IC (Integrated Circuit) that drives the actuator.

[0003] The head also has, 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. This makes it possible to realize, for example, a head (a so-called line head) that has a length spanning the entire width of the recording medium while using a small head body. The frame is a purely structural member and plays no role from an electrical perspective.

[0004] International Publication No. 2021 / 020448

[0005] A liquid ejection head according to one aspect of the present disclosure includes a chip and a rigid wiring substrate. The chip includes a nozzle and an actuator for ejecting liquid from the nozzle. The wiring substrate supports the chip and is electrically connected to the chip.

[0006] A liquid ejection unit according to one aspect of the present disclosure includes the liquid ejection head and a control board configured of a rigid substrate and electrically connected to the liquid ejection head. A plurality of the liquid ejection heads are arranged in a short direction of the wiring board. Each of the plurality of liquid ejection heads has a flexible board connected to the wiring board. Portions of the plurality of flexible boards located on a first side in the 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 so as to overlap the plurality of wiring boards.

[0007] A recording apparatus according to one aspect of the present disclosure includes the liquid ejection head and a transport device that moves the liquid ejection head relative to a recording medium onto which the liquid ejected from the plurality of nozzles lands.

[0008] 1 is a schematic perspective view of a recording apparatus according to an embodiment. A perspective view showing an outline of a liquid ejection head of the recording apparatus of FIG. 1. An exploded perspective view of the liquid ejection head of FIG. 2. A cross-sectional view taken along line IV-IV in FIG. 2. A perspective view showing an outline of a chip of the liquid ejection head of FIG. 2. An exploded perspective view of the chip of FIG. 5. A perspective view of a portion of the chip showing a cross section taken along line VII-VII in FIG. 5. A schematic plan view showing an enlarged view of region VIII in FIG. 2. A cross-sectional view showing another example of a driver IC. A perspective view showing another example (first example) of a flexible substrate. A perspective view showing another example (second example) of a flexible substrate. A perspective view showing another example (third example) of a flexible substrate. A perspective view showing another example (fourth example) of a flexible substrate.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings used in the following description are schematic. Therefore, for example, the dimensional ratios in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional ratios may not match between drawings. Certain shapes and / or dimensions may be exaggerated, and details may be omitted. However, the above does not deny that the actual shapes and / or dimensions may be as shown in the drawings, or that features of shapes and / or dimensions may be extracted from the drawings.

[0010] For convenience, the drawings may include an orthogonal coordinate system D1D2D3. The liquid ejection head and recording apparatus according to the embodiment may be used in any orientation. However, for convenience, terms may be used assuming that the +D3 side is upward.

[0011] 1 is a perspective view that schematically shows 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, when the printing paper P is transported in the 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 the head 3 (either the entire head 3 or at least a portion of the head 3 facing the printing paper P). FIG. 3 is an exploded perspective view of the head 3. The head 3 has a plurality of chips 5 that eject ink droplets (droplets) and directly contribute to printing, and a wiring board 7 (rigid board) that supports the plurality of chips 5. When viewed in the D3 direction (viewing the head 3 from the printing paper P), the plurality of chips 5 are arranged in two staggered rows along the D1 direction. This allows, for example, the use of small chips 5 to achieve a head (a so-called line head) that has a length spanning the entire width of the printing paper P. Of the plurality of chips 5, the chip on the -D2 side is sometimes referred to as chip 5A, and the chip on the +D2 side is sometimes referred to as chip 5B.

[0013] FIG. 5 is a perspective view of the chip 5 (5B) as seen from the printing paper P side. The chip 5 has multiple nozzles 9 that open toward the printing paper P. 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 multiple nozzles 9 may be arranged in any desired arrangement. In the example of FIG. 5, the multiple nozzles 9 are arranged in a staggered pattern in two rows along the D1 direction when viewed in the D3 direction. This makes it possible to form dots on the printing paper P that are arranged in the D1 direction at a pitch narrower than the pitch (e.g., the center-to-center distance) of the nozzles 9 in one row. Of the multiple nozzles 9, the one on the -D2 side is sometimes referred to as nozzle 9A, and the one on the +D2 side is sometimes referred to as nozzle 9B.

[0014] Figure 7 is a perspective view of a portion of the chip 5 (5B) showing a cross section taken along line VII-VII in Figure 5. The chip 5 has 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 Art section, in the comparative example, a flexible substrate was connected to a head body (corresponding to chip 5) having nozzles and actuators. A drive signal (power, from another perspective) was input to the actuator via the flexible substrate. Furthermore, the multiple head bodies (5) were supported by a purely structural member (frame).

[0016] On the other hand, in the embodiment, the multiple chips 5 are supported by a wiring substrate 7. The wiring substrate 7 is also electrically connected to the chips 5. As a result, for example, the wiring substrate 7 contributes to inputting a drive signal to the actuator 11. In this way, in the embodiment, the wiring substrate 7 functions as a member that doubles as the flexible substrate and frame in the comparative example. This reduces the number of parts. As a result, for example, cost reduction and / or miniaturization can be expected.

[0017] The above is an overview of the embodiment. Below, the details of the embodiment will be explained in the following order, starting with the outline: 1. Printer in General (Fig. 1) 2. Head 2.1. Overall Configuration of Head (Figs. 2 to 4) 2.1.1. Overview of Head Components 2.1.2. Overview of Operation of Components 2.2. Chip (Figs. 5 to 7) 2.2.1. Chip in General 2.2.2. Chip Outline 2.2.3. Chip Terminals 2.2.4. Flow Channels and Actuators 2.2.5. Chip Structural Format 2.2.6. Specific Examples of MEMS Chips 2.3. Overview of Wiring Board 2.4. Driver IC 2.5. Control IC 2.6. Flexible Board 2.6.1. Flexible Board in General 2.6.2. Signal Board 2.6.3. Power Board 2.7. Specific Examples of Wiring Board Circuits (Fig. 8) 2.7.1. 2.7.1. Circuits related to signals 2.7.2. Circuits related to power 3. Other examples 3.1. Other examples of driver ICs (FIG. 9) 3.2. Other examples of flexible substrates 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. Others 4. Summary of embodiments

[0018] (1. Printers in General) As already mentioned, 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 print paper P and the transport of the print paper P are performed alternately. For convenience, the explanation of the embodiments may be given assuming a line printer without any particular mention.

[0019] As described above, the printer 1 has four heads 3. A portion 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 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 one 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, the number of heads 3 that the printer 1 has is arbitrary.

[0021] The multiple heads 3 of the unit 13 may be fixed to one another by any suitable method. In the example of Fig. 1, the multiple heads 3 are supported by a support member 15 of the unit 13, and are thereby fixed to one another. The support member 15 has, for example, four openings (not shown) (i.e., the same number as the number of heads 3) that expose the four heads 3 downward.

[0022] The printer 1 prints on, for example, sheets of paper as 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 head 3 in the D1 direction) 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 as printing paper P may be A3 size as defined by "ISO 216." In other words, the head 3 may be capable of printing over a length of 297 mm in the D1 direction.

[0023] The 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 of Fig. 1, a configuration is shown in which the printing paper P is transported by transporting a belt that adsorbs the printing paper P. Other configurations include a configuration in which the printing paper P is transported by rotating rollers that sandwich the printing paper P, and a configuration in which the printing paper P is transported by rotating a drum wrapped around the printing paper P.

[0024] The printer 1 may have, in addition to the head 3 (or, from another perspective, the unit 13) and the transport device 17 already described, a controller 19 that controls the head 3 and the transport device 17. The controller 19 is configured to include, for example, a computer, and controls the head 3 and the transport device 17 (its motor 17a) based on print data that includes image data (which is a broad concept that includes text).

[0025] The printer 1 may have any components other than those described above. For example, the printer 1 may have 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 head 3. Note that the printer 1 may use the head 3 to apply a coating agent in addition to or instead of printing with colored ink.

[0026] (2. Head) (2.1. Overall Configuration of the Head) (2.1.1. Overview of the Components of the Head) As already described, the head 3 shown in FIGS. 2 and 3 has multiple chips 5 and a wiring board 7 on which the multiple chips 5 are mounted. Unlike the example shown, the head (3) may have 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-size 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 wiring board 7, the head 3 includes, for example, the following components: At least one (multiple in the illustrated example) driver IC 21 that drives the actuators 11 of the multiple chips 5; A control IC 23 that controls the driver 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 driver IC 21) mounted on the wiring board 7.

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

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

[0030] The number and arrangement of the drive ICs 21, control ICs 23, signal boards 25, and power boards 27 may be different from those shown in the illustrated example. For example, in the illustrated example, the control ICs 23 and 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.

[0032] As shown in Figures 2 to 4, the multiple chips 5, driver IC 21, and control IC 23 are mounted, for example, on the +D3 side surface of the wiring board 7 (the surface opposite the printing paper P). The wiring board 7 has multiple openings 31 (Figures 3 and 4) that expose the multiple chips 5 on the -D3 side. This allows the chips 5 to eject ink on the -D3 side. The signal board 25 and power board 27 are bonded to the +D3 side surface of the wiring board 7.

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

[0034] For example, in the case where the above-mentioned components not shown are provided, only the combination of the components shown in the figures may be regarded as the head, or only the chip 5 and the wiring board 7 may be regarded as the head. Also, only the combination of the components shown in the figures may be distributed as the head, or only the combination of the chip 5 and the wiring board 7 may be distributed, with the other components being added later.

[0035] (2.1.2. Overview of Operation of Components) Print data input to the controller 19 is converted into a drive signal (e.g., a pulse) having a waveform corresponding to, for example, the amount of droplets to be ejected (or, from another perspective, the size of the dots to be printed), and input to the actuator 11. In the conversion process, the division of roles among the various processing units from the controller 19 to the actuator 11 may be set appropriately. An example of the division of roles is described below.

[0036] The controller 19 causes the head 3 to repeatedly eject droplets at a predetermined printing cycle. This operation, combined with the movement of the print paper P in the direction D2, forms 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 amount of droplets ejected from the plurality of 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 the parallel signal) contained in the input control signal into a parallel signal. This increases the number of control signals transmitted in parallel. The number of control signals output in parallel by the control IC 23 is, for example, equal to or greater than the number of driver ICs 21 (or, from another perspective, chips 5) (for example, an integer multiple of the number of driver ICs 21). In other words, one or more control signals are generated for each driver IC 21. In this case, the control IC 23 may be considered to distribute the input control signal to multiple driver ICs 21, regardless of whether or not a conversion circuit 67 (described later) is present.

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

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

[0040] Note that the first row 29A and the second row 29B are at different positions in the D2 direction (the transport direction of the printing paper P). Furthermore, within each chip 5, the nozzles 9A and 9B are at different positions in the D2 direction. Depending on the configuration of the chip 5, nozzles 9 included in the same row may have different positions in the D2 direction. Depending on such differences in the positions of the nozzles 9 in the D2 direction, the timing at which droplets corresponding to dots at the same position in the D2 direction on the printing paper P are ejected will differ between the nozzles 9. The division of roles related to adjusting for this difference in timing can also be arbitrary.

[0041] (2.2. Chip) (2.2.1. Chip in general) The chip 5 may have a variety of configurations, and may be a known configuration or a configuration that is an application of a known configuration, as long as it has a nozzle 9 and an actuator 11. For example, the method of ejecting ink may be a piezoelectric, thermal, or other method. In a piezoelectric method, ink is ejected by applying pressure to the ink through deformation of a piezoelectric body. In a thermal method, ink is ejected by applying pressure to the ink by heating the ink to generate bubbles. Other methods include, for example, one that uses electrostatic force to attract charged ink, one that uses ultrasonic energy, and one that uses electrostatic force to vibrate the wall of a pressure chamber that contains ink.

[0042] As can be understood from the above, the term "actuator" may be interpreted broadly. That is, the actuator (11) may have various configurations as long as it 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 embodiment, a piezoelectric element will be taken as an example.

[0043] As described above, the multiple chips 5 are arranged in a staggered pattern in, for example, two rows. 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. In different rows, the ends of the chips 5 in the D1 direction overlap each other when viewed in the D2 direction. This makes it possible to print without gaps in the D1 direction. In each row, the pitch (e.g., center-to-center distance) of the multiple chips 5 is generally constant. The chips 5 may also be arranged in three or more rows.

[0044] The size of the chip 5 is arbitrary. The size of the chip 5 may be set from various viewpoints, such as ease of manufacturing, processing precision, and ensuring strength. For example, the length of the chip 5 (direction D1) may be 40 mm or more and 60 mm or less. The width of the chip 5 (direction D2) may be 3 mm or more and 5 mm or less. The thickness of the chip 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 chip 5 in the D1 direction (the direction perpendicular to the direction of relative movement with the print paper P) and the length of the head 3 in the D1 direction (or, from another perspective, the length of the print paper P in the D1 direction). In the examples of Figures 2 and 3, assuming the size of the chip 5 exemplified in the previous paragraph and A3-size print paper P (length in the D1 direction 297 mm), four chips 5 are provided in each row, for a total of eight chips 5.

[0046] The dot density (image resolution) achieved by the chip 5 is arbitrary. From another perspective, the arrangement pattern and number of the multiple nozzles 9 are arbitrary. Examples of dot density are as follows: One chip 5 may have multiple nozzles 9 in an arrangement pattern and number such that the dot density in the D1 direction 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] 5 is a schematic diagram, the nozzles 9 are shown large relative to the size of the chip 5, and the number of nozzles 9 per chip 5 is shown 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 explanation of the number of nozzles 9 (or the number of other elements corresponding to the number of nozzles 9) in the explanation of the embodiment, 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 shown in FIG. 5 is merely an 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 D1 direction. In each row, the multiple nozzles are arranged at a constant pitch, but some randomness may be intentionally imparted. The multiple nozzles 9 arranged in two or more rows are, for example, arranged at different positions in the D1 direction, which contributes to improving resolution. Although a specific embodiment is provided, the chip 5 may have only one nozzle 9.

[0049] (2.2.2. External Shape of Chip) The external shape of the chip 5 is arbitrary. In the example of FIGS. 2 to 5, the chip 5 is roughly a thin rectangular parallelepiped with the D1 direction as the longitudinal direction and the D3 direction as the thickness direction. More specifically, as shown in FIGS. 4 and 5, the chip 5 has a rectangular parallelepiped main body 5e and two flanges 5f protruding on both sides in the D2 direction from the +D3 side of the main body 5e (the side opposite the nozzles 9). 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 opening 31 from the +D3 side. This brings the 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 the wiring board 7 (as in the example of FIG. 4), may be flush with the lower surface, or may be positioned below the lower surface. The main body 5e may contribute to the positioning of the chip 5 and the wiring board 7 by, for example, contacting the inner circumferential surface of the opening 31, or it may not contribute to such positioning.

[0051] The flange 5f engages with the wiring board 7 from the +D3 side around the opening 31. That is, the flange 5f contributes to positioning the chip 5 in the D3 direction relative to the wiring board 7 while inserting the main body 5e into the opening 31. Furthermore, as will be described in detail later, the flange 5f contributes to fixing and / or electrically connecting the chip 5 to the wiring board 7 by bonding the lower surface thereof to the upper surface of the wiring board 7.

[0052] Unlike the illustrated example, the shape of the chip 5 may be, for example, a rectangular parallelepiped. That is, the nozzle surface 5a may be located higher than the upper surface of the wiring substrate 7. Furthermore, in addition to or instead of the flange 5f, a flange may be provided in the D1 direction. In addition to or instead of the flange 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.

[0053] (2.2.3. Chip Terminals) The chip 5 and the wiring board 7 may be electrically connected in any manner. In other words, the terminals of the chip 5 may be provided in any manner. In the illustrated example, the chip 5 has a plurality of terminals 35 ( FIG. 5 ) made of layered conductors on the underside of the flange 5 f. Meanwhile, the wiring board 7 has 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.

[0054] Unlike the illustrated example, for example, a terminal located on the upper surface of the chip 5 and a pad located on the upper surface of the wiring substrate 7 may be connected by a bonding wire. Also, for example, a pin-shaped terminal protruding from the chip 5 may be joined to a pad located on the upper surface of the wiring substrate 7. Also, for example, a pin protruding from the chip 5 may be inserted into the wiring substrate 7 to perform through-hole mounting.

[0055] The terminals 35 and the pads 37 may be joined by any method. For example, an anisotropic conductive film (ACF) connection may be used. More specifically, for example, thermocompression bonding may be performed by sandwiching an ACF between substantially the entire lower surface of the flange 5f and the upper surface of the wiring board 7. The portion of the ACF sandwiched between the terminals 35 and the pads 37 may contribute to fixation and electrical connection. The other portion of the ACF may contribute to fixation (and insulation).

[0056] Alternatively, the terminals 35 and the pads 37 may be joined by solder or a conductive adhesive. As can be seen from the description that bonding wires may be used, the chip 5 and the wiring substrate 7 may be fixed together by an insulating adhesive.

[0057] The terminals 35 include, for example, 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. The potential difference between the reference potential and the drive signal is utilized to drive the actuators 11.

[0058] The number of the plurality of terminals 35D is basically (except for special cases) the same as the number of the plurality of actuators 11 (from another perspective, the plurality of nozzles 9). The plurality of terminals 35D are connected individually (one-to-one) to the plurality of actuators 11. This controls the ejection of liquid for each nozzle 9. 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 plurality of terminals 35D, or may be different (for example, may be fewer).

[0059] The specific shape, dimensions, and arrangement of the terminals 35D and 35G are arbitrary. In the example of FIG. 5, all of the terminals 35D are located on the flange 5f adjacent to the driver IC 21 in the D2 direction (the -D2 side for chip 5B and the +D2 side for chip 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 and are arranged at a constant pitch in the D1 direction (the longitudinal direction of the chip 5). The multiple terminals 35G have, for example, the same shape and dimensions 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 terminal 35D. A single terminal 35G that is long in the D1 direction may be provided.

[0060] (2.2.4. Flow Channel and Actuator) As will be understood from the above description, the ink flow channel (including the nozzle 9) and the actuator 11 may have any configuration. An example is shown below.

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

[0062] As shown in Figures 6 and 7, a common flow path 47 opens onto the top surface of the chip 5. Ink is supplied to the common flow path 47 from a flow path member (not shown) that is overlaid on the top surface of the chip 5. As shown in Figure 7, a plurality of individual flow paths 49 communicate with the common flow path 47. Each individual flow path 49 has, in order from the common flow path 47 side, a supply path 49a, a pressure chamber 51, and a nozzle 9. Ink from the common flow path 47 is replenished into the pressure chamber 51 via the supply path 49a. Liquid is ejected from the nozzle 9 when pressure is applied to the pressure chamber 51 by the actuator 11.

[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 toward the center of the chip 5 in the width direction. The multiple individual flow paths 49 generally extend from the common flow path 47 to one side or the other in the width direction of the chip 5, and a nozzle 9 is located at the tip of each individual flow path 49. The nozzle 9 opens directly into the pressurizing chamber 51.

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

[0065] 7 is a so-called unimorph type piezoelectric actuator. The actuator 11 has, for example, a vibration plate 53, a lower electrode 55, a piezoelectric body 57, and an upper electrode 59, in that order from the pressure chamber 51 side. These, for example, generally 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, so that the actuator 11 bends toward the pressure chamber 51 or the opposite side like a bimetal. This bending deformation is used to apply pressure to the pressure chamber 51, causing ink to be ejected from the nozzle 9.

[0067] (2.2.5. Chip Structural Type) The outline of the chip 5, the terminals 35, the flow paths (47 and 49), the actuator 11, and the like described so far may be realized by any of a variety of structural types. For example, the 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 technology 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, with respect to the chip 5, are, for example, the flow paths (47 and 49), the actuator 11, and the terminals 35.

[0068] In a MEMS chip including multiple chip substrates, each chip substrate may have 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 stack 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 on 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 above thin film using photolithography; and etching of the base substrate 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 a plan view.

[0070] Unlike the above description, the chip 5 does not have to be a MEMS chip. For example, the chip 5 may be formed by bonding a flow path member including the nozzle 9 and an actuator substrate including the actuator 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 have recesses and / or through holes that 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 is applied in a predetermined pattern.

[0071] (2.2.6. Specific Example of MEMS Chip) When the chip 5 is configured by a MEMS chip, the specific configuration thereof is arbitrary. An example is shown below.

[0072] 6, the chip 5 is configured, for example, by stacking multiple (four in the illustrated example) chip substrates (as already described) in the D3 direction 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 of the printing paper P).

[0073] The nozzle substrate 39 has, for example, a plurality of nozzles 9. The actuator substrate 41 has, for example, a plurality of actuators 11, and has flow paths that supply ink to the plurality of nozzles 9. The support substrate 43, for example, contributes to the reinforcement of the nozzle substrate 39 and the actuator substrate 41, and has 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 has, for example, flow paths and circuits that lead to the flow paths and circuits of the support substrate 43, and also has a flange 5 f.

[0074] These chip substrates may be bonded together by an appropriate bonding method. For example, the chip substrates may be bonded directly without an adhesive, or may be bonded together using an adhesive. Note that in FIG. 7, the adhesive may be omitted regardless of whether direct bonding is used. The thickness of each chip substrate may be set appropriately depending on the functions required of each chip substrate. 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 follows, for example:

[0076] 7, the nozzle substrate 39 is configured by forming a plurality of nozzles 9 on a base substrate using microfabrication technology. The base substrate is, for example, a silicon substrate. The shape and dimensions of the nozzles 9 are arbitrary.

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

[0078] The base substrate 41a is, for example, a silicon substrate. The pressure chamber 51 and a part of the supply path 49a are formed on the base substrate 41a by microfabrication technology. The specific shapes and dimensions of the pressure chamber 51 and the supply path 49a are not limited.

[0079] The laminated film 41b has, for example, at least four layers including the above-mentioned diaphragm 53, lower electrode 55, piezoelectric body 57, and upper electrode 59. Although not particularly shown, the laminated film 41b may include layers other than those described above. For example, the laminated film 41b may have an insulating layer that covers the metal layer to prevent ink from contacting the metal layer, or an insulating layer that covers the metal layer including the lower electrode 55 and the metal layer including the upper electrode 59 to insulate them 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 the illustrated example, a vibration plate 53 may be provided for each pressure chamber 51. The vibration plate 53 closes the upper surface of the pressure chamber 51. In the example of FIG. 7, the vibration plate 53 also contributes to closing the portion of the supply path 49a formed in the base substrate 41a. The vibration plate 53 (or, from another perspective, the laminated film 41b) has a through-hole (see also FIG. 6) that forms the portion of the supply path 49a that leads to the common flow path 47. The vibration plate 53 may be made of any material, such as an insulating material or the same material as the piezoelectric element 57.

[0081] The lower electrode 55 is applied with, for example, a reference potential. 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 of FIG. 7 , a lower electrode 55 is provided for each pressure chamber 51. Unlike the example shown in the figure, the lower electrode 55 may extend across the multiple pressure chambers 51.

[0082] 7, the metal layer (reference potential layer) including the lower electrode 55 has, for example, a wiring (reference numeral omitted) extending from the lower electrode 55 to the side of the terminal 35G already described (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 the support substrate 34. In the example of FIG. 6, the terminal 61G is common to a plurality of actuators 11.

[0083] Unlike the illustrated example, a plurality of terminals 61G may be formed individually on a plurality of actuators 11. The metal layer including the lower electrode 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 electrode 55 and the metal layer including the upper electrode 59 may be insulated from each other via an insulating layer (or a layer including the piezoelectric element 57) (not shown).

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

[0085] A drive signal, for example, is input to the upper electrode 59 (individual electrode). 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, approximately the same shape and size as the pressure chambers 51 in a plan view.

[0086] 7, the metal layer including the upper electrode 59 has, for example, a wiring (reference numeral omitted) extending from the upper electrode 59 to the side of the terminal 35D already described (the -D2 side in the case of 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 on a base substrate (reference numeral omitted) using microfabrication technology. As described above, the base substrate is, for example, a silicon substrate. The shapes formed on the base substrate include, for example, a through-hole (slit) that forms a portion of the lower side of the common flow path 47, and a recess (groove) that accommodates the actuator 11 and is formed on the underside of the base substrate. The conductor formed on the base substrate is, for example, a through-conductor 43b that connects terminals 61D and 61G of the actuator substrate 41 to terminals 35D and 35G on the underside of the flange 5f.

[0088] The relay substrate 45 is formed wider in the D2 direction than the support substrate 43. As a result, the previously described flange 5f is formed by the edge of the relay substrate 45. The relay substrate 45 is formed by forming an appropriate shape and conductors on a base substrate (reference numeral omitted) using microfabrication technology. As previously described, the base substrate is, for example, a silicon substrate. The shape formed on the base substrate is, for example, a through-hole (slit) that forms a portion of the upper side 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, ACF 63. This electrically connects the plurality of terminals 61D and 61G of the actuator substrate 41 to the plurality of through conductors 43b of the support substrate 43 individually. The support substrate 43 and the relay substrate 45 are bonded together via, for example, ACF 65. This electrically connects the plurality of through conductors 43b of the actuator substrate 41 to the plurality of terminals 35D and 35G of the relay substrate 45 individually.

[0090] (2.3. Overview of Wiring Board) The wiring board 7 shown in Figures 2 to 4 may be of any type as long as it is a rigid board. For example, the wiring board 7 may be a single-sided board having a conductor layer on only one side of an insulating board, a double-sided board having conductor layers on both sides of an insulating board, or a multi-layer board having three or more conductor layers. Furthermore, the wiring board 7 having two or more conductor layers may be a build-up type in which insulating layers and conductor layers are sequentially formed on the top surface of a core insulating board, or may be a type in which combinations of insulating layers and conductor layers are bonded together. The material of the insulating board is also arbitrary, and may be, for example, resin, ceramic, or glass.

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

[0092] The pattern of the conductor layer of the wiring board 7 (or, from another perspective, the circuit configuration) is arbitrary as long as it is possible to mount the chip 5 and to electrically connect the chip 5 to other electrical elements (here, the driving IC 21). In the illustrated example, the wiring board 7 is configured so that the driving IC 21 and the control IC 23 can be mounted thereon. Unlike the illustrated example, for example, the wiring board 7 may be configured to simply act as an intermediary between the chip 5 and the flexible substrate, and the driving IC 21 and the like may be mounted on the flexible substrate. Even in this case, the degree of freedom in the connection position and shape of the flexible substrate is improved compared to, for example, an embodiment in which a flexible substrate is connected to multiple chips 5.

[0093] The wiring board 7 (its circuit) may simply have wiring, or may have 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 has electronic elements, the electronic elements may be either built-in or embedded. The former electronic elements are, for example, manufactured integrally with the substrate portion of the wiring board 7 at the same time as the wiring board 7 is manufactured. In the latter electronic elements, for example, a pre-manufactured electronic element (e.g., an IC chip) is 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 has a conversion circuit 67 that increases the number of control signals transmitted in parallel (performs serial-to-parallel conversion). The conversion circuit 67 may be, for example, a built-in type. More specifically, the conversion circuit 67 may be, for example, an LTPS circuit included in the LTPS substrate serving as the wiring board 7.

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

[0096] As can be understood from the above description, the wiring board 7 relays signals from the signal board 25 to the chip 5. More specifically, the signal relaying includes the following: Relaying a control signal from the signal board 25 to the control IC 23; Relaying a control signal from the control IC 23 to the conversion circuit 67; Relaying a control signal from the conversion circuit 67 to the driver IC 21; and Relaying a drive signal from the driver IC 21 to the chip 5. The layout of the wiring relating to these relays is arbitrary. An example will be described later ( FIG. 8 ).

[0097] Furthermore, the wiring board 7 distributes the power supplied from the power board 27 (which, in another sense, is a reference potential and a potential having a predetermined potential difference from the reference potential) to, for example, the circuits (e.g., the conversion circuit 67), the driver IC 21, and the control IC 23 included in the wiring board 7. Furthermore, the wiring board 7 applies the reference potential applied from the power board 27 to, for example, the terminal 35G of the chip 5 (which, in another sense, is the lower electrode 55). The arrangement of the wiring related to these power supplies 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 the "power supply potential."

[0098] (2.4. Driver IC) The driver IC 21 shown in FIGS. 2 to 4 is, for example, a chip-type component. The driver IC 21 may have a package surrounding a semiconductor substrate, or may be a bare chip without a package. The driver IC 21 may be mounted in any manner. In the example shown in FIG. 4, the driver IC 21 has terminals 21a (an example of an input section) made of a layered conductor on its underside and is surface-mounted on the wiring substrate 7. Other embodiments include, for example, the various embodiments described in the description of the chip 5 (mounting using bonding wires, surface mounting of 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 an ACF (not shown), similar to the chip 5. Of course, solder or a conductive adhesive may also be used. As can be understood from the above description, the driver IC 21 may be mounted using COG (chip-on-glass) mounting.

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

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

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

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

[0103] In the illustrated example, the arrangement range of the driver ICs 21 in the D2 direction is roughly the same as the arrangement range of the chip 5 in the D2 direction, 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 chip 5, while also ensuring an area for forming wiring 81 (see FIG. 8) that connects the driver ICs 21 and chip 5 that are adjacent to each other in the D2 direction.

[0104] The driver IC 21 outputs a drive signal to the upper electrode 59 (individual electrode) of the actuator 11 via the wiring board 7. The drive signal is, for example, a signal having a waveform that causes (and / or releases) bending deformation in the actuator 11, and is generally pulsed. An example of the process by which print data is converted into a drive signal has already been described. In addition to the control signal, the driver 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 driver IC 21 generates a drive signal of a desired waveform from the DC voltage, for example.

[0105] (2.5. Control IC) The description of the driver IC 21 may be appropriately applied to the control IC 23, except for its location and role. 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 optional, and may or may not be COG mounting. The shape, dimensions, and location of the control IC 23 are optional.

[0106] 2 and 3, the control IC 23 is smaller in size than the chip 5 and the driver IC 21. Of course, this does not have to be the case. Also, 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 on the longitudinal end side (+D1 side) of the wiring board 7 relative to the chips 5 and the driver ICs 21. The position of the control IC 23 in the width direction (D2 direction) of the wiring board 7 is set to 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 the above. For example, the control IC 23 may be adjacent to the +D1 side of the driver IC 21 that is furthest to the +D1 side among the staggered arrayed drive ICs 21, and may be adjacent to the chip 5 furthest to the +D1 side in the D2 direction.

[0108] (2.6. Flexible Board) (2.6.1. Flexible Boards in General) A flexible board (signal board 25 and power board 27 shown in FIGS. 2 and 3) connected to the wiring board 7 may not be provided. For example, instead of a flexible board, a connector into which another rigid board is inserted may be mounted on the wiring board 7. Furthermore, the flexible board does not have to be provided as a combination of the signal board 25 and the two power boards 27. For example, a single flexible board having the functions of the signal board 25 and the power board 27 may be provided.

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

[0110] The flexible substrates (25 and 27) 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 substrates may have circuits that function as active elements or the like, or may have electronic components (e.g., ICs) mounted thereon.

[0111] The thickness of the flexible substrates (25 and 27) is arbitrary, for example, 0.2 mm or less. The thickness of the conductor layer (or, from another perspective, the wiring) of the flexible substrate is also arbitrary. For example, the thickness of the conductor layer of the flexible substrates (25 and 27) is thicker than the thickness of the conductor layer of the wiring substrate 7 (e.g., an LTPS substrate). As a result, for example, the wiring resistance of the power substrate 27 is smaller than that of the wiring substrate 7, and the likelihood of a drop in power supply potential is reduced.

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

[0113] (2.6.2. Signal Board) As will be understood from the above explanation, the signal board 25 inputs the 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 the signal board 25 may be output directly from the signal board 25, or may be output after undergoing predetermined processing (for example, 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 in the longitudinal direction of the wiring board 7 closer to the short edge 7b on the +D1 side than the control IC 23 (the opposite side to the multiple chips 5 and multiple driver ICs 21). More specifically, the joining area is roughly the end of the wiring board 7 on the +D1 side. The position of the connection position in the D2 direction is set to the center position of the width of the wiring board 7. Unlike 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 signal board 25 may extend (spread) in any direction from the connection position with the wiring board 7. In the illustrated example, the signal board 25 extends from the connection position toward the +D1 side. From another perspective, the portion (end) 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 numeral shown in FIG. 2) that is connected to other components on the controller 19 side. Unlike 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 planar shape of the signal board 25 is roughly rectangular, more specifically, a rectangular shape with the D1 direction as the longitudinal direction. When the signal board 25 is not bent and is formed into a planar shape parallel to the wiring board 7, the signal board 25 fits within the width of the wiring board 7 and extends outward from the short edge 7b on the +D1 side of the wiring board 7 to the +D1 side. Unlike the illustrated example, the signal board 25 does not have to have such a width and length.

[0117] (2.6.3. Power Board) The power board 27 supplies power (e.g., DC power of a predetermined voltage) supplied from a power supply circuit (not shown) included in the main body or head 3 of the printer 1 to the wiring board 7. The power input to the power board 27 may be output directly from the power board 27, or may be output after undergoing predetermined processing (e.g., transformation and / or division into powers of different voltages).

[0118] The connection position of the power board 27 to the wiring board 7, the direction in which the power board 27 extends from the connection position, and the shape and dimensions of the power board 27 are arbitrary. In the examples of Figures 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, a plurality of connection positions are regularly distributed over a relatively long range in the D1 direction (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 to one side in the longitudinal direction of the wiring board 7 (the -D1 side in the illustrated example). This one side is opposite the side from which the signal board 25 extends. From another perspective, the portion (end) of each power board 27 located on the -D1 side of the multiple connection positions on the wiring board 7 is a connection portion 27a (reference numeral shown in FIG. 2) that is connected to other components on the controller 19 side. When the power board 27 is not bent and is made flat and parallel to the wiring board 7, it has 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 have to have such a length.

[0121] Assume that the power board 27A is not bent but is formed into a flat surface parallel to the wiring board 7. In this case, the power board 27A has a shape that extends linearly in the D1 direction with a generally constant width (in other words, an elongated shape that follows the long edge 7a on the -D2 side). Furthermore, in a planar view, the power board 27A is contained within the area between the first row 29A (from another perspective, the multiple chips 5A and / or multiple driver ICs 21A) and the long edge 7a on the -D2 side (it 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 the tolerance range. Unlike the illustrated example, the power board 27A may not protrude beyond the long edge 7a on the -D2 side, but may overlap the driver ICs 21 and / or chips 5. The same applies to power board 27B as described above for power board 27A, except that the first column 29A and the word -D2 are replaced with the second column 29B and the word +D2.

[0122] (2.7. Specific Examples of Circuits on Wiring Board) As described above, the wiring board 7 relays signals and power. Pads and wiring for this purpose can be arranged in various ways. An example is shown below.

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

[0124] First, we will describe the path from pad 69, to which signal board 25 is connected, to pad 37, to which chip 5 is connected (the pad to which drive signals are input), and then we will describe the path from pads 83A, 83B, and 83C, to which power board 27 is connected.

[0125] (2.7.1. Signal-Related Circuits) The pads 69 to which the signal board 25 is connected are located approximately at the longitudinal end of the wiring board 7. If the distance between the pads 69 and the short edges 7b is shorter than the length of the pads 69 in the D1 direction, the pads 69 may be considered to be located at the end 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] The wiring 71 extending from the pad 69 is part of a plurality of pads 73 to which terminals (not shown) of the control IC 23 are bonded, and is connected to the same number of pads 73 as the pads 69. The pad 73 to which the wiring 71 is connected is located closer to the pad 69 than the other pads 73. The control IC 23 and the pads 69 are aligned generally in the D1 direction, and therefore the wiring extends generally in the D1 direction.

[0127] The pads 73 are arranged in two rows in the D2 direction. Unlike 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. A plurality of wirings 75 extend from some of the pads 73 that are not connected to pad 69.

[0128] The plurality of wirings 75 transmit control signals distributed by the control IC 23 to the driving ICs 21. The number of wirings 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 driving ICs 21. In Fig. 8, the same number (8) of wirings 75 as the number of driving ICs 21 is illustrated as an example.

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

[0130] The wiring 75 generally extends toward the long edge 7a and then extends along the long edge 7a toward the −D1 side (the side where the driver IC 21 and the like are arranged). The wiring 75 also extends between the first column 29A (and the −D2 side conversion circuit 67) and the long edge 7a on the −D2 side, or between the second column 29B (and the +D2 side conversion circuit 67) and the long edge 7a on the +D2 side.

[0131] The multiple wirings 75 extending on the +D2 side correspond to the second column 29B and are connected to the conversion circuit 67 corresponding to the second column 29B. The multiple wirings 75 on the +D2 side are connected to the conversion circuits 67 in order starting from the wirings on the -D2 side, and extend toward the -D1 side in decreasing numbers.

[0132] Similarly, the multiple wirings 75 extending on the −D2 side correspond to the first column 29A and are connected to the conversion circuit 67 corresponding to the first column 29A. The multiple wirings 75 on the −D2 side are connected to the conversion circuits 67 in order starting from the +D2 side, and extend toward the −D1 side in decreasing numbers.

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

[0134] A plurality of wires 77 (four in FIG. 8 ) extend from each conversion circuit 67 toward the center of the wiring board 7 in the width direction. The plurality of wires 77 transmit control signals input in parallel to the driving ICs 21 by the conversion circuits 67. The number of wires 77 extending from one conversion circuit 67 is the same as the number of control signals input in parallel to the driving ICs 21, and is the same as the number of actuators 11 (nozzles 9) controlled by one driving IC 21, for example. As described above, this number may be as large as, for example, 100 or more and 10,000 or less. For convenience, FIG. 8 shows an extremely small number of wires 77, that is, four.

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

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

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

[0138] The multiple wirings 81 are connected to some of the multiple pads 37 to which the chip 5 is bonded, and are located toward the center of the width of the wiring substrate 7 (the side of the driver IC 21 to which the chip 5 is adjacent in the D2 direction). In the illustrated example, the pitch of the multiple pads 37 is greater than the pitch of the multiple pads 79. Therefore, the multiple wirings 81 extend at different angles inclined relative to the D2 direction. In other words, the multiple wirings 81 are all arranged in a roughly trapezoidal region. Of course, if the difference in pitch between the two is in another manner, the multiple wirings 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, it may be difficult to provide the wiring 81 connected to the ends of each chip 5 on the same plane. In such cases, the wiring 81 may be provided so as to overlap each other with an insulating layer interposed therebetween.

[0140] 8 shows pads 79 and 37 as dummy pads that are not connected to any circuitry and are only used for balancing the junctions. Such dummy pads do not necessarily have to be provided.

[0141] (2.7.2. Circuits Related to Power) One of the pads 83A and 83B is supplied with a reference potential from the power board 27, and the other is supplied with a power supply potential from the power board 27. The pads 83A and 83B contribute to supplying power to the driver 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] 8 , the paths from pads 83A to 83C to control IC 23 are omitted from illustration. Pad 73 related to these paths is also omitted from illustration. These paths are arbitrary. For example, a line may be provided that applies a reference potential from pad 83C closest to +D1 to pad 73, and a line may be provided that applies a power supply potential from pad 83B closest to +D1 to pad 73.

[0143] The pads 83A and 83B are located roughly on the edge portion on the long edge 7a side of the wiring board 7. Note that, for example, if the distance between the pads 83A and 83B and the long edge 7a is shorter than the length of the pads 83A and 83B in the D2 direction, the pads 83A and 83B may be considered to be 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 plurality of wires 75 extending along one long edge 7a.

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

[0145] The pads 83A and 83B are provided in the same number as the number of driver ICs 21, for example. On each of the -D2 side and +D2 side, the pads 83A are located on the -D1 side of each driver IC 21, and the pads 83B are located on the +D2 side. From another perspective, the same number of pads 83A (pads 83B) as the number of driver ICs 21 are arranged at the same pitch as the driver ICs 21. Unlike 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 driver ICs 21.

[0146] The pads 83A and 83B supply power to, for example, the nearest one of the plurality of conversion circuits 67 and the plurality of driving ICs 21. FIG. 8 illustrates an example in which power is supplied to one driving IC 21 (and the corresponding conversion circuit 67) from the pads 83A and 83B located on both sides of the driving IC 21. That is, two wirings 85 extend from the pads 83A and 83B on both sides of the driving IC 21 and connect to two pads 79 and the conversion circuit 67. The routing of the wirings 85 is arbitrary. In FIG. 8, the wiring 85 extends to cross the wiring 75 via an insulating layer (not shown). Either of the wirings 75 and 85 may be located above the other.

[0147] Pad 83C is located between chip 5 and long edge 7a on the same side in the D2 direction, and further between chip 5 and multiple wirings 75 on the same side in the D2 direction. Pad 83C applies a reference potential to chip 5 adjacent to it in the D2 direction. More specifically, one or more wirings 87 (two in FIG. 8) extend from one pad 83C. The wirings 87 are connected to the pads 37 that are located on the pad 83C's side in the D2 direction, 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 the pad 83C in the D1 direction is, for example, located at the center in the D1 direction of the chip 5. From another perspective, the multiple pads 83C are arranged at the same pitch as the pitch of the multiple chips 5.

[0149] The shape and extending direction of the multiple wirings 87 are arbitrary. Unlike the illustrated example, the wirings 87 do not have to have a linear shape. For example, the wirings 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 pads 83A to 83C described above is repeated on the -D1 side of the range shown in Figure 8. Therefore, although not specifically shown, except for the chip 5 (5B) closest to the -D1 side and the chip 5 (5A) closest to the +D1 side, pads 83B, 83C, and 83A are lined up in order from the -D1 side at equal intervals between each chip 5 and the adjacent long edge 7a. At this position, the multiple wirings 75 bend inward of the wiring board 7 on both sides of pad 83C in the D1 direction to avoid pads 83B and 83A.

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

[0152] (3. Other Examples) Below, examples different from the examples described so far will be described. In the following description, basically, only differences from the examples described relatively earlier will be described. Matters not specifically mentioned may be considered to be the same as the examples described earlier or may be inferred from the examples described earlier. Below, for convenience, corresponding components in different examples may be assigned the same reference numerals even if there are differences.

[0153] (3.1. Another Example of the Driver IC) FIG. 9 is a cross-sectional view showing another example of the driver IC, and corresponds to FIG.

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

[0155] The shape and size of the driving IC 221 may be the same as or different from the shape and dimensions of the driving IC 21. The example of Fig. 9 illustrates an aspect in which the top surface of the driving IC 221 is lower than the top surface of the driving IC 21, and therefore lower than the top surface of the chip 5. On the other hand, the dimension of the driving IC 221 in the D2 direction (and / or the D1 direction, not specifically shown) is larger than that of the driving IC 21. For example, the length of the driving IC 221 in the D2 direction is longer than the length of the opening 31 in the D2 direction (and further the length of the chip 5 in the D2 direction).

[0156] The driving IC 221 does not have a terminal (see terminal 21a in FIG. 4) that is joined to the wiring board 207, and the signal input section is a conductor of the wiring board 207. The conversion circuit 67 may be provided in a manner that is distinguishable from the driving IC 221, or in a manner that is indistinguishable from the driving IC 221. Although not particularly shown, the control IC may also be provided on the wiring board 207 (for example, an LTPS circuit) like the driving IC 221. In other words, the driving IC and / or the control IC may be provided on the wiring board.

[0157] (3.2. Other Examples of Flexible Board) (3.2.1. First Example) FIG. 10 is a diagram showing another example of a power board, and corresponds to FIG.

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

[0159] In head 303, the distance between connection portion 27a and pads 83A-83C (FIG. 8) farthest from connection portion 27a is roughly half that of head 3. Also, the width of the wiring inside power board 27 can be doubled. As a result, for example, the likelihood of the power supply potential affecting power board 27 is reduced. Furthermore, head 3 is advantageous in terms of miniaturization compared to head 303, because power board 27 is pulled out in only one longitudinal direction.

[0160] (3.2.2. Second Example) FIG. 11 is a diagram showing another example of a power board, and corresponds to FIG.

[0161] In the head 3 of Fig. 2, the power board 27 is fitted 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 the head 403 of Fig. 11, the power board 427 protrudes outward from the long edge 7a (not shown in Fig. 11 as it is hidden by the power board 427). More details are as follows, for example.

[0162] Suppose the power board 427 is not bent but is formed into a flat surface parallel to the wiring board 7 (see the power board 427A on the -D2 side). In this case, the power board 427 has an extension 427e having a portion extending along the long edge 7a on the outside of the long edge 7a, and multiple branch portions 427f extending from the extension 427e toward the inside of the long edge 7a and connected to the pads 83A to 83C ( FIG. 8 ). The entire extension 427e may be located outside the long edge 7a (including a mode 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 half or at least two-thirds of the width (in the D2 direction) of the extension 427e may be located outside the long edge 7a.

[0163] As shown by the power board 427B on the -D2 side, the power board 427 may be used in a state in which the extending portion 427e is bent relative to the branch portion 427f (of course, it may also 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 in the D3 direction, or so that it overlaps the wiring board 7, and may be configured so that it does not protrude from the long edge 7a in a plan view of the wiring board 7, or may protrude from it. The power board 427 may be maintained in a bent state by another member (for example, the flow path member, heat sink, or housing described above) abutting against the extending portion 427e.

[0164] The position of the branch portion 427f corresponds to the position of the pads 83A to 83C. As described with reference to FIG. 8, for example, three pads 83A to 83C (or two pads) are lined up in the center of each chip 5 in the D1 direction. FIG. 8 illustrates branch portions 427f provided in common to the three pads 83A to 83C. Although not specifically shown, when a pad 83A or 83B that is not adjacent to the 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 may be provided individually for each pad.

[0165] The shape and dimensions of the branch portion 427f are arbitrary. For example, when the power board 427 is made flat, the end of the branch portion 427f on the side of the extending portion 427e (or, from another perspective, the edge of the extending portion 427e on 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] 11, the power board 427 has external connection portions 427a on both longitudinal sides, similar to the example in FIG. 10. Unlike the illustrated example, the power board 427 may have connection portions 427a only on the -D1 side or the +D1 side. Also, although not specifically illustrated, the power board 427 having a portion extending outward from the long edge 7a may have no branch portions 427f. In other words, the power board 427 may simply be the power board 27 widened outward from the long edge 7a.

[0167] (3.2.3. Third Example) FIG. 12 is a diagram showing another example of a power board, and corresponds to FIG.

[0168] In the head 3 of Fig. 2, the power board 27 extends along the long edge 7a and is connected to the plurality of pads 83A to 83C (Fig. 8) arranged along the long edge 7a, whereas in the head 503 of Fig. 12, the plurality of power boards 527 are arranged along the long edge 7a and are connected to the plurality of pads 83A to 83C arranged along the long edge 7a.

[0169] 11, the power board 527 can be regarded as a power board 527 in which the extension 427e has been eliminated and the branch 427f has been made into the power board 527. Therefore, the explanation of the branch 427f (for example, the point that it is provided in correspondence with the positions of the pads 83A to 83C) may be applied to the power board 527 as long as no contradictions arise.

[0170] For example, when the power board 527 is not bent but is made flat and parallel to the wiring board 7, it extends outward from the long edge 7a from the connection position with the wiring board 7. From another perspective, the portion (end) of the power board 527 located on the −D2 side or +D2 side of the joining position with the wiring board 7 forms a connection portion 527a that is connected to other components on the controller 19 side.

[0171] As with the power board 427, the power board 527 may be used with the portion of the long edge 7 a extending outward bent relative to the portion joined to the wiring board 7 (although, of course, it may also be used without being bent). In this regard, the description of the power board 427 may be applied to the power board 527.

[0172] 13 is a perspective view showing another example of a power board. In this figure, a unit 613 having a plurality of heads 603 (four in the illustrated example) is shown, similar to FIG. 1.

[0173] In head 603, the power board 27 extends out from the same side as the signal board 25, unlike head 3. The power board 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 shown by the two-dot chain lines, the power board 27 and the signal board 25 may be used in a state where they are bent so that the control board 33 overlaps the wiring board 7 (of course, they 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, the −D2 side, and / or the +D2 side. The same applies to the power board 27 and the signal board 25. Unlike the illustrated example, the power board 27 and the signal board 25 may be bent so that the control board 33 is aligned along the D3 direction.

[0175] (3.3. Other) In the example of FIG. 4, the chip 5 is mounted on the upper surface (+D3 side) of the wiring substrate 7. From another perspective, the direction in which the chip 5 is bonded to the wiring substrate 7 (towards the -D3 side) is the same as the direction in which the nozzle 9 opens (towards the -D3 side). Conversely to the above, the chip 5 may be mounted on the lower surface of the wiring substrate. From another perspective, the direction in which the chip 5 is bonded to the wiring substrate 7 may be opposite to the direction in which the nozzle 9 opens.

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

[0177] 7, the edges of the relay substrate 45 on the −D2 side and the +D2 side may be removed to expose the through conductors 43b, and the through conductors 43b may be joined to the pads 37 on the underside of the wiring substrate 7. The relay substrate 45 may be inserted into the opening 31 of the wiring substrate 7.

[0178] (4. Summary of the embodiment) In the following, specific configurations of the embodiment will be extracted and their actions and effects will be illustrated. Note that in the following description, for convenience, the reference numerals in Figures 1 to 8 will be used preferentially. However, the following description also applies to the examples in Figures 9 to 13 unless a contradiction arises.

[0179] The liquid ejection head (head 3) has a chip 5 and a rigid wiring board 7. The chip 5 has a nozzle 9 and an actuator 11 for ejecting liquid from the nozzle 9. The wiring board 7 supports the chip 5 and is electrically connected to the chip 5 (i.e., the chip 5 is mounted on the wiring board 7).

[0180] Therefore, as described in the description of the outline of the embodiment, the wiring board 7 functions as both a flexible substrate and a frame in the comparative example (see the background art section). In other words, the number of parts is reduced. As a result, for example, cost reduction and / or miniaturization can be expected.

[0181] The head 3 may have a plurality of chips 5 supported on the same wiring substrate 7 .

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

[0183] The chip 5 may be a MEMS chip, and the wiring substrate 7 may be an LTPS substrate.

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

[0185] The head 3 may further include (at least one) driver IC 21 that drives the actuator 11. The driver 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 actuator 11 but also contributes to the placement of the driving IC 21. As a result, the number of parts is further reduced compared to, for example, an embodiment in which the driving IC 21 is mounted on a flexible board connected to the wiring board 7 (this embodiment may also be included in the technology according to the present disclosure). As a result, for example, cost reduction and / or miniaturization can be expected.

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

[0188] In this case, for example, the process of fabricating the driver IC 21 separately from the wiring board 7 or mounting the driver IC 21 on the wiring board 7 is not required. As a result, for example, cost reductions can be expected. Also, the driver IC 221 as an LTPS circuit does not need to ensure the strength required for the driver IC 21 as a chip, so it can be made thinner. Consequently, it is expected that the head 3 can be made thinner.

[0189] In a plan view of the wiring substrate 7 (or, from another perspective, viewed in the direction of the opening of the nozzle 9), the plurality of chips 5 may be arranged in a staggered pattern. The driving 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 realizing a head 3 capable of printing over a range longer than the length of the chips 5 (direction D1) using multiple chips 5, if there is only one row of chips 5, there will be areas between adjacent chips 5 where no printing occurs. 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 substrate 7 where no chips 5 are located. This dead space can be used as a placement position for the driver IC 21. As a result, the head 3 is made smaller. This is made possible by using the wiring substrate 7 as a member supporting the multiple chips 5, and is a configuration that is impossible with the configuration of the comparative example described in the background art.

[0191] In a plan view of the wiring substrate 7, a plurality of chips may be arranged in a staggered pattern in two rows. In a plan view of the wiring substrate 7, a plurality of driver 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 a plurality of chips 5.

[0192] In this case, the dead space can be more effectively utilized. Furthermore, since the chips 5 and the driver ICs 21 are adjacent to each other, the structure of the wiring 81 and other components of the wiring substrate 7 for connecting the chips 5 and the driver ICs 21 can be simplified. This in turn makes it easier to reduce the size of the wiring substrate 7 in plan view, for example.

[0193] In a configuration in which multiple chips 5 and multiple driving ICs 21 are arranged in a staggered pattern, the wiring substrate 7 may connect adjacent chips 5 and driving ICs 21 in a direction (direction D2) intersecting the row of multiple chips 5 (first row 29A or second row 29B).

[0194] In this case, for example, it is easy to match one chip 5 with one driver IC 21, improving the effect of simplifying the wiring 81, etc. 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 81, etc. is also improved from this perspective.

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

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

[0198] In this case, for example, the number of wires 81 after the conversion circuit 67 (on the driver IC 21 side) is greater than the number of wires 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 driver ICs 21 are provided at the end of the wiring board 7 in the D1 direction, the area required for the multiple wires 75 and the multiple wires 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 a control IC 23 that inputs signals to the plurality of drive ICs 21 via a first circuit (a 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 (the +D1 side) in the longitudinal direction (the D1 direction) 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 than in a configuration in which the control IC 23 is provided on another board connected to the wiring board 7 (this configuration may also be included in the technology disclosed herein). Furthermore, while connections to external elements (signal board 25) for the wiring board 7 are concentrated at one end of the wiring board 7, the conversion circuit 67 for each driver IC 21 as described above reduces the area required for the multiple wirings 75 and the multiple wirings 81. As a result, the signal board 25 and wiring board 7 as a whole are smaller than in a configuration in which external elements (corresponding to the signal board 25) are directly connected to the conversion circuit 67 (this configuration may also be included in the technology disclosed herein). Furthermore, the wiring board 7 can be thinner than in a configuration in which the control IC 23 is located closer to the long edge 7a than the conversion circuit 67 (this configuration may also be included in the technology disclosed herein). As a result, for example, it is easier to arrange multiple heads 3 in a narrow range in the D2 direction. As a result, for example, the degree of freedom in the configuration of the transport device 17 is improved.

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

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

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

[0204] In this case, the power board 27 is extended outward in the longitudinal direction of the wiring board 7. This makes it easier to narrow the head 3 including the power board 27 (reducing its size in the direction D2) compared to an embodiment in which the power board 27 is extended outward in the lateral direction of the wiring board 7 (e.g., the example of FIG. 12 ). As a result, for example, it is easier to arrange multiple heads 3 in a narrow range in the direction D2. On the other hand, if the power board 27 is only located at the longitudinal end of the wiring board 7 like the signal board 25 (such an embodiment may also be included in the technology disclosed herein), there is a possibility that the power supply potential supplied to the driving IC 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 board with thin wiring). However, by having the power board 27 extend along the long edge 7 a and connect 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 made flat parallel to the wiring board 7, it may extend along the first long edge (the long edge 7a on the -D2 side) inside the first long edge when viewed from above.

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

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

[0208] In this case, for example, compared to a configuration in which the power board 27 is fitted inside the long edge 7 a, the wiring width can be made wider and the wiring resistance can be reduced, thereby reducing the likelihood of voltage drop, for example.

[0209] The head 503 (FIG. 12) may have a flexible substrate (power substrate 527) that supplies power to the multiple driver ICs 21. The wiring substrate 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 (D1 direction) of the wiring substrate 7 in a plan view. The multiple chips 5 and multiple driver ICs 21 may be arranged along the D1 direction to form a first row 29A on the -D2 side and a second row 29B on the +D2 side. The multiple power substrates 527 on the -D2 side may be arranged along the long edge 7a on the -D2 side and connected to the wiring substrate 7 between the first row 29A and the long edge 7a on the -D2 side.

[0210] In this case, it is easier to increase the width of the wiring and reduce the wiring resistance compared to an embodiment having a power board 27 (or 427) that extends along the long edge 7 a. Note that an embodiment having a long power board 27 can reduce the number of external connections 27 a compared to an embodiment having multiple power boards 527, which is advantageous for making the head 3 smaller.

[0211] In a configuration in which the signal board 25 is located on the first side (+D1 side) in the longitudinal direction of the wiring board 7, the head 603 (FIG. 13) may further include a flexible board (power board 27A) that supplies power to the drive IC 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 a plurality of positions in the D1 direction between the first row 29A and the long edge 7a on the −D2 side, and may have external connection portions 25a in a portion that extends toward the first side (+D1 side) beyond the above-mentioned plurality of positions (and / or the first row 29A and further 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, cost reductions can be expected. Note that in the embodiment in which the signal board 25 and the power board 27 are pulled out on opposite sides (FIG. 2), for example, it is easy to reduce the size or multiply the functions of each of the two boards individually connected to the signal board 25 and the power board 27.

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

[0214] In this case, for example, the effect of reducing the number of parts can be achieved, and the area of ​​the unit 613 in a plan view can be reduced, thereby making it possible to reduce the size of the printer 1 including the unit 613.

[0215] The 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 by a user and moves relative to the recording medium. The recording device may also be one 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, and 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 to prepare chemicals. Specifically, the head may eject a predetermined amount of 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, but may be, for example, paint or a conductive material printed on a printed wiring board.

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

Claims

1. A liquid ejection head comprising: a chip having a nozzle and an actuator for ejecting liquid from the nozzle; and a rigid wiring board that supports the chip and is electrically connected to the chip.

2. The liquid ejection head according to claim 1, comprising a plurality of said chips supported on the same wiring substrate.

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

4. A liquid ejection head according to any one of claims 1 to 3, further comprising a drive IC for driving the actuator, the drive IC being mounted on the wiring board or included in the wiring board.

5. The liquid ejection head according to claim 4, wherein the driving IC is constituted by an LTPS circuit provided on the wiring board.

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

7. A liquid ejection head as described in claim 6, wherein, in a planar view of the wiring board, a plurality of the chips are arranged in a staggered pattern in two rows, and, in a planar view of the wiring board, a plurality of the driving ICs are arranged in a staggered pattern in two rows so as to be positioned between the plurality of the chips.

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

9. A liquid ejection head as described in claim 7 or 8, wherein the wiring board has, in a plan view, a first long edge and a second long edge extending parallel to each other in the longitudinal direction of the wiring board, the plurality of chips and the plurality of driving ICs are arranged along the longitudinal direction to form a first row on the side of the first long edge and a second row on the side of the second long edge, and the wiring board has a first circuit located between the first row and the first long edge for inputting signals to the plurality of driving ICs in the first row.

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

11. A liquid ejection head as described in claim 9 or 10, further comprising a control IC that inputs signals to a plurality of the driving ICs via the first circuit, the control IC being mounted on the wiring board or included in the wiring board at a position on the first side of the wiring board in the longitudinal direction relative to the first row.

12. A liquid ejection head as described in claim 11, further comprising a signal board made of a flexible substrate which inputs signals to the control IC via the wiring board, the signal board being connected to the wiring board at a connection position on the first side of the control IC, and having a connection portion with the outside in a portion extending from the connection position to the first side when the signal board is not bent and is made flat parallel to the wiring board.

13. A liquid ejection head as claimed in any one of claims 7 to 12, further comprising a power board made of a flexible substrate and applying a first potential to the plurality of driving ICs, wherein the wiring board has, in a plan view, a first long edge and a second long edge extending parallel to each other in the longitudinal direction of the wiring board, the plurality of chips and the plurality of driving ICs are arranged along the longitudinal direction to form a first row on the side of the first long edge and a second row on the side of the second long edge, and when the power board is not folded and made into a flat surface parallel to the wiring board, the power board extends along the first long edge and is connected to the wiring board between the first row and the first long edge and at a plurality of first positions in the longitudinal direction for applying the first potential, and has connection portions to which the first potential is applied from outside at a portion extending outward in the longitudinal direction from all of the plurality of first positions.

14. A liquid ejection head as described in claim 13, wherein when the power board is not bent and is made 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 when viewed from above.

15. A liquid ejection head as described in claim 13, wherein the first substrate, when not bent and formed into a flat surface parallel to the wiring board, has an extension portion that extends along the first long edge on the outside of the first long edge, and a plurality of branch portions that extend from the extension portion to the inside of the first long edge and are connected to the plurality of first positions.

16. A liquid ejection head as described in any one of claims 7 to 12, further comprising a power board made of a flexible substrate which supplies power to the plurality of driving ICs, the wiring board having a first long edge and a second long edge which extend parallel to each other in the longitudinal direction of the wiring board in a planar view, the plurality of chips and the plurality of driving ICs being arranged along the longitudinal direction to form a first row on the side of the first long edge and a second row on the side of the second long edge, and the plurality of power boards being arranged along the first long edge and connected to the wiring board between the first row and the first long edge.

17. A liquid ejection head as described in claim 12, further comprising a power board made of a flexible substrate that supplies power to a plurality of the driving ICs, the power board extending along the first long edge and connected to the wiring board at a plurality of positions in the longitudinal direction between the first row and the first long edge, and having a connection portion with the outside in a portion extending toward the first side beyond the plurality of positions.

18. A liquid ejection unit comprising: a liquid ejection head according to any one of claims 1 to 17; and a control board constituted by a rigid board electrically connected to the liquid ejection head, wherein a plurality of the liquid ejection heads are arranged in the short direction of the wiring board, each of the plurality of liquid ejection heads has a flexible board connected to the wiring board, and portions of the plurality of flexible boards located on a first longitudinal side 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 so as to overlap the plurality of wiring boards.

19. A recording device comprising: a liquid ejection head according to any one of claims 1 to 17; and a transport device that relatively moves the liquid ejection head and a recording medium on which the liquid ejected from the nozzles lands.

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