JP4967755B2 - Head module, liquid discharge head, liquid discharge apparatus, and method of manufacturing head module - Google Patents

Description

  The present invention includes a common flow path member for forming a common flow path that communicates with all liquid chambers of the head chip, drives each energy generating element of the head chip via a wiring substrate, and supplies liquid in each liquid chamber. The present invention relates to a head module that discharges liquid in each liquid chamber by applying a discharge force to the liquid, a liquid discharge head and a liquid discharge device that use a plurality of the head modules, and a method of manufacturing such a head module. More specifically, the present invention relates to a technique that allows a head module to be configured with only three components, that is, a head chip, a wiring board, and a common flow path member.

  Conventionally, as an example of a liquid ejecting apparatus, a line head type ink jet printer in which nozzles for ejecting ink (liquid) are arranged in a length corresponding to the width of a recording sheet is known. A line head (liquid discharge head) used in such an ink jet printer has a heating resistor (energy generating element) for discharging ink disposed so as to face the nozzle, and drives the heating resistor from the nozzle. Ink is discharged.

  The line head type ink jet printer which enables printing corresponding to the width of the recording paper by such a line head is a serial type ink jet which performs printing by moving the serial head (liquid ejection head) in the width direction of the recording paper. Compared with a printer, there is an advantage that not only vibration and noise are reduced, but also the printing speed can be significantly increased because no means for moving the recording paper in the width direction is required.

Here, as a line head, a technique is known in which a relatively small head chip on which a heating resistor is arranged is arranged in one direction to form a head chip row. As a method for manufacturing individual head chips, a method using a semiconductor manufacturing technique is known. That is, a heating resistor is formed on a semiconductor substrate such as silicon, and a sacrificial layer is formed on the upper portion thereof with a soluble resin. Further, a coating layer to be a structure is formed on the sacrificial layer, and a nozzle is formed in this coating layer. Thereafter, a through hole is formed in the semiconductor substrate from the back surface of the semiconductor substrate, and a sacrificial layer is dissolved from the through hole, thereby manufacturing a head chip in which a heating resistor and a nozzle are formed on the semiconductor substrate (for example, , See Patent Document 1).
Japanese Patent No. 3343875

A technique is also known in which a through hole is not formed in a semiconductor substrate. That is, a semiconductor substrate, a heating resistor provided on the semiconductor substrate, a coating layer provided on the semiconductor substrate and provided with a nozzle on the heating resistor, a region on the heating resistor and the outside communicate with each other. A head chip in which a through hole communicating with the individual flow path is not formed in the semiconductor substrate, and a common flow path penetrating the semiconductor chip. An ink supply member to which the head chip is bonded so as to communicate with the path, and a top plate that is disposed so as to straddle the covering layer of the head chip and the ink supply member and seals a portion through which the ink supply member passes. This is a technique provided (see, for example, Patent Document 2).
JP 2006-1112 A

  By the way, when a single line head is manufactured by arranging a plurality of head chips in one direction, if a defect occurs in only a part of the line head due to a defective head chip or the like, the entire line head becomes defective. Become. Therefore, it is difficult to control the quality of the line head, resulting in inferior mass productivity, and even if the line head is partially broken, it is necessary to replace the entire line head, resulting in high repair costs. There is.

Therefore, a technique for configuring a line head by combining a plurality of head modules is known. That is, several head chips are arranged and fixed in a module frame having a length that is a fraction of the width of the recording paper, and wiring of a wiring board is connected to the electrodes of each head chip. Head module. By combining a plurality of these head modules, a line head corresponding to the width of the recording paper is obtained (for example, see Patent Document 2).

JP 2005-138528 A

  According to such a modular line head, production and quality control can be performed in units of head modules, so that it is possible to expect a reduction in the defect rate and an accompanying increase in mass productivity. In terms of service, it is efficient because only the defective head module needs to be replaced. Furthermore, line heads of various sizes can be easily provided by changing the number and combination of the head modules, which enables efficient design and manufacture.

  However, the technique described in Patent Document 1 requires a process of making a through hole in a semiconductor substrate, which complicates the manufacturing process and increases the manufacturing time. Therefore, the yield is poor and the cost is high. Further, since the through hole is formed in the semiconductor substrate, the rigidity of the head chip is lowered, and in order to obtain a modular line head, the head chip is mounted on the module frame as in the technique described in Patent Document 3 above. Therefore, the module frame is indispensable.

  On the other hand, in the technique described in Patent Document 2, since the through hole is not formed in the semiconductor substrate, the problem caused by the through hole does not occur as in the technique described in Patent Document 1, but the ink supply member A top plate is required to seal the penetrating part. For this reason, the number of parts increases, and in particular, in a line head in which a plurality of head chips are arranged, the number of steps and labor of the assembly process increase, which is complicated.

Moreover, in the technique described in Patent Document 3, a module frame is indispensable for fixing the head chip. As a result, the number of parts increases, and the productivity and assembly of the head module and line head deteriorate.
Therefore, the problem to be solved by the present invention is to reduce the number of parts and improve the productivity and assemblability of the head module and line head.

The present invention solves the above-described problems by the following means.
According to the first aspect of the present invention, a plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and each of the energy generating elements and the control substrate are provided. A head chip provided with electrodes for electrical connection, a wiring board having wiring for electrically connecting the electrodes of the head chip and the control board, and all the liquids of the head chip A common flow path member for forming a common flow path that communicates with the chamber, and drives each energy generating element of the head chip via the wiring substrate to give a discharge force to the liquid in each liquid chamber Accordingly, in the head module for discharging the liquid in each of the liquid chambers, the common flow path member includes a hollow common flow path forming portion opened on one side and the common flow path shape. A head chip support part for supporting the head chip within the opening surface of the part, and a wiring board support part for supporting the wiring board covering the opening surface of the common flow path forming part, The head chip is supported by the head chip support portion so that each of the liquid chambers and the common flow channel communicate with each other, and the wiring substrate forms the common flow channel with the common flow channel forming portion. As described above, it is supported by the wiring board support part.

  A sixth aspect of the invention relates to a liquid discharge head using a plurality of head modules according to the first aspect, and a seventh aspect of the invention relates to the head module according to the first aspect. The present invention relates to a plurality of liquid ejection devices. Furthermore, the invention described in claim 8 and claim 12 relates to the method of manufacturing the head module described in claim 1.

(Function)
In each of the above inventions, the common flow path member for forming a common flow path that communicates with all the liquid chambers of the head chip includes a hollow common flow path forming portion that is open on one side, and a common flow path forming portion. A head chip support portion for supporting the head chip within the opening surface and a wiring substrate support portion for supporting the wiring substrate covering the opening surface of the common flow path forming portion are provided. The head chip is supported by the head chip support portion so that each liquid chamber communicates with the common flow path, and the wiring substrate forms a common flow path with the common flow path forming section. It is supported by the wiring board support part. Therefore, the head chip is supported by the common flow path member, and the head chip can be fixed without using a module frame that is necessary in the prior art. Further, since the wiring board covers the opening surface of the common flow path forming portion, the common flow path can be formed without using a top plate that is necessary in the conventional technique.

  According to the present invention, the head chip is supported by the common flow path member, and the common flow path can be formed by the wiring board. Therefore, the head module can be configured with only three parts of the head chip, the wiring board, and the common flow path member. As a result, the number of parts is reduced, and the productivity and assembly of the head module and line head are greatly improved.

Embodiments of the present invention will be described below with reference to the drawings.
In the following embodiments, a color inkjet printer that ejects four colors of ink (liquid), Y (yellow), M (magenta), C (cyan), and K (black), as the liquid ejection apparatus of the present invention. Will be described as an example. The liquid discharge head according to the present invention is a line head 1 used in the color ink jet printer, and the head module according to the present invention is a head module 10 constituting the line head 1.

FIG. 1 is a plan view showing the line head 1 of the present embodiment, as viewed from the ink ejection surface side.
As shown in FIG. 1, the line head 1 is obtained by fixing a plurality of head modules 10 to a head frame 2 with screws 3. In other words, two head modules 10 are arranged in series in the longitudinal direction in the head module placement hole 2a of the head frame 2 to form a head module row 10a, and each head module row 10a forms an A4 recording sheet. Covers the width of. The head module row 10a is arranged in four rows (four rows in parallel), and ink of four colors of Y (yellow), M (magenta), C (cyan), and K (black) is provided for each row. Discharge.

  Here, each head module 10 has two rows of head chip rows 20a in which four head chips 20 are arranged in one direction. Then, each head chip 20 in each head chip row 20a is on the back side (the side opposite to the ink ejection surface) of the flexible wiring board 30 having flexibility (corresponding to the wiring board in the present invention). Eight are arranged in a staggered manner and are electrically connected to the flexible wiring board 30. The flexible wiring board 30 has an opening 30a for allowing ink ejected from each head chip 20 to pass therethrough.

  Each head module 10 includes a buffer tank 40 (corresponding to the common flow path member in the present invention) on the back side of the flexible wiring board 30. The buffer tank 40 is for forming a common flow path for ink ejected from each head chip 20, and is joined to the flexible wiring substrate 30 so as to cover the top of each head chip 20. Therefore, each head chip 20 in one head module 10 ejects one color ink in the buffer tank 40.

FIG. 2 is a partial cross-sectional perspective view showing the head chip 20 in the head module 10 of the present embodiment.
As shown in FIG. 2, the head chip 20 is provided with a plurality of heating resistors 22 (corresponding to the energy generating elements in the present invention) for discharging ink, and each of the heating resistors 22 is flexible. An electrode 23 for electrically connecting the wiring substrate 30 (see FIG. 1) is provided. Further, the head chip 20 is formed with nozzles 25 a for ejecting ink so as to face the heating resistors 22. As the energy generating element of the present invention, a heating element other than the heating resistor 22 (such as a heater), a piezoelectric element such as a piezoelectric element, or the like can be used.

  Here, the head chip 20 can be manufactured using semiconductor technology. For example, the heating resistor 22 is formed on one surface of the semiconductor substrate 21 made of Si (silicon) or the like using Ta (tantalum). In addition, on the same side as the surface on which the heat generating resistor 22 of the semiconductor substrate 21 is formed, the edge opposite to the edge on which the heat generating resistor 22 is formed is for receiving power and signals supplied from the outside. The electrode 23 is formed. Furthermore, a drive element 24 (N-type MOS transistor) for the heating resistor 22 is formed between the heating resistor 22 and the electrode 23.

  Thereafter, a positive type photoresist (PMER-LA900, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for forming an ink liquid chamber 26 (corresponding to the liquid chamber in the present invention) is spun so as to surround the heating resistor 22. It is applied by coating so that the film thickness becomes 10 μm. Then, after exposure with a mask aligner, development is performed with a developer (tetramethylammonium hydroxide 3% aqueous solution), and a rinse process is performed with pure water to form a resist pattern corresponding to the ink liquid chamber 26. Further, the entire surface of the resist pattern is exposed with a mask aligner and left to stand for 24 hours in a nitrogen atmosphere.

  Next, the nozzle formation layer 25 is laminated on the resist pattern and the semiconductor substrate 21. That is, the rotational speed is adjusted so that the film thickness on the resist pattern becomes 10 μm, and a photocurable negative photoresist is applied to the region including the driving element 24 by spin coating. And after exposing with a mask aligner, it develops with a developing solution (Tokyo Ohka Kogyo Co., Ltd. product OK73 thinner), rinses with a rinse liquid (IPA), and the nozzle formation layer 25 is laminated | stacked. Further, a nozzle 25 a (diameter 15 μm) is formed in the nozzle forming layer 25 so as to face the heating resistor 22.

  Subsequently, the resist pattern is completely dissolved and eluted while being immersed in an organic solvent (PGMEA) having solubility in a resist pattern (positive photoresist) corresponding to the ink liquid chamber 26. Then, after cleaning is performed to form the ink liquid chamber 26, gold bumps are attached to the electrodes 23, and the semiconductor substrate 21 is cut into a desired size to form the head chip 20.

  In such a head chip 20, the arrangement pitch of each heating resistor 22 and each nozzle 25a is about 42.3 μm, and has a resolution of 600 dpi. As shown in FIG. 1, eight head chips 20 are arranged in a staggered manner to form the head module 10, and the end portions of the two head modules 10 are overlapped and arranged in series, thereby A resolution of 600 dpi is maintained over the entire width of the recording paper.

  Each ink liquid chamber 26 of the head chip 20 is formed on the semiconductor substrate 21. That is, the surface of the semiconductor substrate 21 on which the heating resistor 22 is formed constitutes the bottom wall of the ink liquid chamber 26, and the portion of the nozzle forming layer 25 that surrounds the heating resistor 22 in a substantially concave shape forms the side wall of the ink liquid chamber 26. The surface of the nozzle forming layer 25 on which the nozzles 25 a are formed forms the top wall of the ink liquid chamber 26. Therefore, the lower left direction in FIG. 2 opens without providing a through hole or the like in the semiconductor substrate 21, and ink can be supplied into the ink liquid chamber 26 from this opening. As a result, the rigidity of the head chip 20 is maintained by the semiconductor substrate 21.

  Further, the ink supplied into the ink liquid chamber 26 is ejected by driving the heating resistor 22. That is, by driving the heating resistor 22 by the driving element 24, the ink in the ink liquid chamber 26 corresponding to the heating resistor 22 is ejected from the nozzle 25a. Therefore, the flexible wiring board 30 (see FIG. 1) is connected to the electrode 23. As shown in FIG. 1, in the head module 10 of this embodiment, since eight head chips 20 are arranged in a staggered manner, the flexible wiring board 30 includes the electrodes 23 of the eight head chips 20. Connected.

FIG. 3 is a partial perspective view showing the connection relationship between the head chip 20 and the flexible wiring board 30 in the head module 10 of the present embodiment. In FIG. 3, a part of the flexible wiring board 30 is turned over for easy understanding of the drawing.
As shown in FIG. 3, each head chip 20 is mounted on the back side of the flexible wiring board 30. And the flexible wiring board 30 has the wiring 31 for electrically connecting each electrode 23 of each head chip 20 and the control board 4 (not shown) mentioned later. Therefore, each heating resistor 22 (see FIG. 2) of each head chip 20 is electrically connected to the control board 4 via each electrode 23 and each wiring 31.

  Here, the flexible wiring board 30 has a so-called sandwich structure in which each wiring 31 is sandwiched between polyimide resin films from both sides, and has flexibility. Each wiring 31 is formed by attaching a copper foil on a polyimide resin film and then etching the wirings 31. Each electrode 23 of each head chip 20 (for circuit power supply and heating resistor driving) is formed. , Clock wiring, data communication, grounding, other control signals, etc.).

  The flexible wiring board 30 has an opening 30a. The opening 30a is for allowing ink ejected from each nozzle 25a of the head chip 20 to pass through, and is formed by pressing a die for cutting with a blade against the flexible wiring board 30 and punching it out. Has been. The opening 30a may be formed using a laser, a drill, or the like.

  With respect to such a flexible wiring board 30, the head chip 20 is bonded to the flexible wiring board 30 so that each nozzle 25a is positioned in the opening 30a. At this time, since the positioning mark is attached to the flexible wiring board 30, the head chip 20 is mounted in accordance with the positioning mark. In addition, since the adhesive sheet that is melted by heat is attached to the back surface side of the flexible wiring substrate 30 at the portion where the nozzle forming layer 25 (see FIG. 2) of the head chip 20 contacts, When heat is applied, adhesion between the head chip 20 and the flexible wiring board 30 is completed.

  Furthermore, the vicinity of the opening 30 a is a connection portion 31 a for connecting the wiring 31 to each electrode 23 of each head chip 20. Since each wiring 31 and each electrode 23 in the connection portion 31a face each other at the mounting position of the head chip 20, if pressure and heat are applied only to the facing portion, each electrode 23 and each wiring with gold bumps attached thereto. 31 is connected. The connection between each electrode 23 and each wiring 31 is not limited to a bump, and may be performed by a flying lead or a wire bond.

FIG. 4 is a plan view showing the flexible wiring board 30 in the head module 10 of the present embodiment, as viewed from the ink ejection surface side.
As shown in FIG. 4, when eight head chips 20 are bonded to the opening 30a of the flexible wiring board 30, head chip rows 20a in which the four head chips 20 are arranged in one direction are arranged in two rows. The head chips 20 in each head chip row 20a are arranged in a staggered manner.

  Here, since the opening 30a of the flexible wiring board 30 is opened with a size larger than each nozzle 25a (see FIG. 3) of the head chip 20, the flexible wiring board 30 does not get in the way when ink is ejected. In addition, the accuracy of attaching the head chip 20 may be as long as the flexible wiring board 30 does not block the nozzles 25a. Therefore, the eight head chips 20 can be arranged in a staggered manner by simple assembly using a jig or the like.

  In addition, power, signals, and the like are sent to each head chip 20 via the flexible wiring board 30. That is, the flexible wiring board 30 includes a connection portion 31a for connecting the wiring 31 (see FIG. 3) to the electrode 23 (see FIG. 3) of each head chip 20 in each head chip row 20a, and each head chip row. A common wiring portion 31b in which a plurality of wirings 31 common to the head chips 20 in 20a are combined, and a terminal portion 31c for connecting the wiring 31 to the control board 4 (not shown) are provided.

  Furthermore, since the head chip rows 20a are arranged in two rows, the connecting portions 31a are respectively arranged outside the two opposing head chip rows 20a, and the common wiring portions 31b are respectively arranged outside the connecting portions 31a. Has been. Since the terminal portion 31c is only on one head chip row 20a side (in FIG. 4, one side below the flexible wiring board 30), the other head chip row 20a side (in FIG. 4, flexible wiring board 30). In order to guide the common wiring portion 31b on the upper side) to the terminal portion 31c, a connecting portion 31d for connecting the two common wiring portions 31b is provided. Therefore, the portion of the connecting portion 31d including the connecting portion 31a becomes an ink ejection surface, and the opening 30a is formed in the connecting portion 31d.

  As described above, the flexible wiring board 30 includes the two connecting portions 31a and the two common wiring portions 31b corresponding to the two head chip rows 20a, and the two common wiring portions 31b are connected to the connecting portion 31d. Connected and grouped into one terminal portion 31c. The connection part 31a, the connection part 31d, and the terminal part 31c have a single-layer structure in which the respective wirings 31 (see FIG. 3) are arranged in the horizontal direction, and the wirings 31 of the common wiring part 31b are overlapped in the vertical direction. It has a multi-layer structure having a portion formed.

FIG. 5 is a plan view showing a wiring structure of the flexible wiring board 30 in the head module 10 of the present embodiment.
As shown in FIG. 5, each wiring 31 of the flexible wiring board 30 is connected to each electrode 23 of each head chip 20 by a connection portion 31a. Therefore, each wiring 31 of the connection part 31a has a single layer structure in which the number corresponding to each electrode 23 is arranged in the horizontal direction.

  Here, each electrode 23 of each head chip 20 is divided into a circuit power source, a heating resistor drive, a clock, a data communication, a ground, and other control signals. Not only the head chips 20 that are individually required but also those common to all the head chips 20. That is, the ejection data to be transmitted to the head chip 20 and the signal that conveys the state of the head chip 20 are different for each head chip 20, but other signals and electrodes for supplying power are all the head chips 20. Is common. Therefore, some of the wirings 31 of the connection part 31a can be shared.

  Therefore, the wirings 31 that can be shared are collectively used as a common wiring part 31b. As shown in FIG. 5, the common wiring part 31b is arranged along the longitudinal direction of the flexible wiring board 30, and only those that can be shared among the wirings 31 of the connection part 31a are connected. Therefore, it is possible to reduce the number of wirings 31 of the flexible wiring board 30 while enabling ejection control for each head chip 20. In addition, the common wiring portion 31b has a multilayered wiring 31 having portions that are stacked in the vertical direction, and the direction of the wiring 31 is switched by 90 °, so that the width required for the wiring 31 of the flexible wiring board 30 is reduced. can do.

  On the other hand, the connection portion 31a has a single-layer structure in which the wirings 31 are arranged in the horizontal direction. However, the width required for the wirings 31 is determined by the number of arrangements of the head chips 20, so that there is no particular problem. On the contrary, if the wiring 31 of the connection part 31a has a multi-layer structure, the flexible wiring board 30 (the ejection surface of the head chip 20) where the head chip 20 is attached becomes thick, so the opening 30a (FIG. 4). (See) is a large concave shape. As a result, ink, dust, and the like are easily collected in the opening 30a. Therefore, in the connection portion 31a, the wiring 31 has a single layer structure so that the ejection surface of the head chip 20 is thin (the opening 30a is shallow).

  In addition, the two common wiring portions 31b of the flexible wiring board 30 are connected by the connecting portion 31d, but since the plurality of wirings 31 common to each head chip 20 are already collected in the common wiring portion 31b, The number of wirings 31 of the connection part 31d is also significantly reduced compared to the connection part 31a. Therefore, the connecting portion 31d that crosses the ejection surface of the head chip 20 can have a single-layer structure arranged in the horizontal direction in parallel with the wiring 31 of the connecting portion 31a. As a result, the head module of the present embodiment. 10 can thin the discharge surface of the head chip 20 in the flexible wiring board 30. In addition, since the number of wirings 31 crossing the ejection surface of the head chip 20 is small, the distance between the head chips 20 arranged in a staggered manner can be reduced as much as possible, and a presser or the like is used to eject ink. The width direction of the head module 10 that cannot be installed can be made compact.

  As described above, the eight head chips 20 are arranged in a staggered manner on the flexible wiring board 30, and the wiring 31 is connected to each electrode 23 of each head chip 20. Each wiring 31 of the head chip row 20a (see FIG. 4) on the terminal portion 31c (see FIG. 4) side has a single-layer structure terminal section from the single-layer connection section 31a through the multi-layer common wiring section 31b. Each wiring 31 of the head chip row 20a on the opposite side to the terminal portion 31c is led from the connection portion 31a having a single layer structure to a common wiring portion 31b having a multilayer structure, a connecting portion 31d having a single layer structure, and a multilayer structure. Through the common wiring portion 31b to the terminal portion 31c having a single layer structure. The terminal part 31c has a single-layer structure in order to connect the wiring 31 to the control board 4 (not shown).

  A buffer tank 40 (see FIG. 1) is joined to the flexible wiring board 30 so as to cover the upper part of each head chip 20. In other words, a common flow path communicating with all the ink liquid chambers 26 (see FIG. 2) of each head chip 20 is formed, and flexible so that ink ejected from each head chip 20 can be supplied to all the ink liquid chambers 26. A buffer tank 40 is bonded onto the wiring substrate 30 and each head chip 20.

FIG. 6 is a plan view showing the buffer tank 40 in the head module 10 of the present embodiment, as viewed from the ink ejection surface side.
As shown in FIG. 6, the buffer tank 40 includes a hollow common flow path forming portion 41 that opens on one side. Then, a common flow path for ink is formed by the common flow path forming portion 41 and becomes a supply source of ink to the ink liquid chamber 26 (see FIG. 2). Ink is supplied from the ink supply port 42 to the common flow path.

  Further, the buffer tank 40 includes a head chip support portion 43 for supporting each head chip 20 (see FIG. 2) so that the common ink flow path and the ink liquid chamber 26 (see FIG. 2) communicate with each other. Yes. Furthermore, a wiring board support 44 is provided to support the flexible wiring board 30 (see FIG. 4). Furthermore, a positioning mark for joining the flexible wiring board 30 is provided. Then, each head chip 20 and the flexible wiring board 30 and the buffer tank 40 are joined to form the head module 10 of the present embodiment. The buffer tank 40 has a screw hole 45, and the head module 10 can be fixed to the head frame 2 (see FIG. 1) through the screw hole 45.

FIG. 7 is a plan view showing the head module 10 of the present embodiment, as viewed from the ink ejection surface side.
As shown in FIG. 7, in the head module 10, the flexible wiring board 30 is supported by the wiring board support portion 44 of the buffer tank 40, and each head chip 20 is supported by the head chip support portion 43 of the buffer tank 40. Yes.

  Here, in each head chip 20, each electrode 23 (see FIG. 3) of the head chip 20 and each wiring 31 (see FIG. 3) of the flexible wiring board 30 face each other, and from each nozzle 25a (see FIG. 3). The ejected ink is attached to the flexible wiring board 30 so that the ink can pass through the openings 30a of the flexible wiring board 30. Therefore, after the adhesive is applied to the buffer tank 40, the flexible wiring board 30 to which each head chip 20 is bonded is joined to the buffer tank 40, whereby the head module 10 shown in FIG. 7 is obtained.

  Accordingly, each head chip 20 is supported by each head chip support 43 simultaneously with the bonding of the flexible wiring board 30 to the wiring board support 44 of the buffer tank 40. The opening surface of the common flow path forming portion 41 is covered by the flexible wiring board 30, and a common ink flow path is formed between the flexible wiring substrate 30 and the common flow path forming portion 41.

  Further, each head chip 20 is supported in the opening surface of the common flow path forming portion 41, and each ink liquid chamber 26 (see FIG. 2) communicates with the common flow path of ink. Since the rigidity of each head chip 20 is maintained by the semiconductor substrate 21 (see FIG. 2), even if the head chip 20 is directly supported by the head chip support portion 43, the head chip 20 may be broken. There is no. As a result, only three parts of the head chip 20, the flexible wiring board 30, and the buffer tank 40 are required (a module frame is not required as in Patent Documents 1 and 3, and a top plate is required as in Patent Document 2). Therefore, the head module 10 of this embodiment can be configured with a small number of parts).

FIG. 8 is a partial cross-sectional view showing the periphery of the head chip 20 in the head module 10 of the present embodiment.
As shown in FIG. 8, the head chip 20 is fixed to the head chip support portion 43 of the buffer tank 40 by an adhesive. Further, the flexible wiring board 30 is also joined to the buffer tank 40. Note that the head chip 20 and the flexible wiring board 30 are attached to each other with the nozzle formation layer 25 so that the ink discharged from the nozzles 25a can pass through the openings 30a.

  As described above, the head module 10 is obtained by bonding the head chip 20 and the flexible wiring board 30 to the buffer tank 40. A common flow path for ink is formed by the common flow path forming portion 41 of the buffer tank 40, and this common flow path communicates with the ink liquid chamber 26 of the head chip 20. That is, the buffer tank 40 forms a common ink flow path common to all the head chips 20 in one head module 10, and temporarily stores the ink supplied to the ink liquid chamber 26.

  Further, in the flexible wiring board 30, the wiring 31 is connected to the electrode 23 of the head chip 20 through the connection portion 31a. And the common wiring part 31b of the flexible wiring board 30 exists in the outer side of the buffer tank 40, and the flexible wiring board 30 is connected with the control board 4 (not shown) by the terminal part 31c (refer FIG. 4).

  When such a head module 10 selectively drives the heating resistor 22 via the drive element 24 in accordance with a command from the control board 4 (not shown), the ink liquid chamber corresponding to the heating resistor 22 is provided. Ink 26 can be ejected from the nozzle 25a. That is, in a state where the ink liquid chamber 26 is filled with ink, a pulse current for a short time (for example, 1 to 3 μsec) is passed through the heating resistor 22 based on a command from the control board 4. Then, since the heating resistor 22 is rapidly heated, ink is boiled and bubbles are generated at a portion in contact with the heating resistor 22, and a certain volume of ink is pushed away by the expansion of the bubbles. As a result, ink having a volume equivalent to the pushed ink is ejected as ink droplets from the nozzle 25a, and printing is performed.

  Further, in order to maintain the print quality, it is necessary to perform a recovery operation that removes ink, dust, and the like accumulated in the vicinity of the nozzle 25a. Since it has a structure, ink, dust and the like can be easily removed from the vicinity of the nozzle 25a. That is, the connection portion 31a serving as the ink ejection surface has a shallow opening 30a because the flexible wiring board 30 does not become thick unlike the common wiring portion 31b having a multilayer structure. Specifically, the thickness of the common wiring portion 31b having a multilayer structure is about 130 μm, whereas the thickness of the connection portion 31a and the opening 30a having a single layer structure is as thin as about 50 μm. Therefore, if the periphery of the opening 30a is wiped with a thin rubber blade or the like, excess ink or dust can be easily removed.

  Further, one line head 1 is configured by using a plurality of such head modules 10. That is, as shown in FIG. 1, the rigid head frame 2 is formed with a head module arrangement hole 2a. In the head module arrangement hole 2a, eight head modules 10 are arranged in the head module arrangement hole 2a. The two head modules 10 are connected in series, and the head modules 10 connected in series are arranged in four stages. Each head module 10 is screwed to the head frame 2 by screws 3 and positioned. At this time, the common wiring portion 31 b of the flexible wiring board 30 is bent upward along the side surface of the buffer tank 40.

FIG. 9 is a plan view showing the line head 1 in a state where all the head modules 10 of this embodiment are arranged on the head frame 2, and is a view seen from the surface opposite to FIG.
As shown in FIG. 9, each head module 10 is arranged in the head module arrangement hole 2 a of the head frame 2.

  Here, as shown in the AA sectional view of the head module 10, the flexible wiring board 30 is bent upward along the side surface of the buffer tank 40. That is, since the flexible wiring board 30 has flexibility, it can be bent easily. The connecting portion 31a (contact portion 31d) of the single-layer structure of the flexible wiring board 30 is used as an ink discharge surface, and both sides are formed so that no step is generated on the discharge surface and the width of the discharge surface is not widened. The common wiring portion 31b having the multilayer structure is bent to place the head module 10 in the state shown in the AA sectional view in the head module placement hole 2a. Then, the terminal portion 31c of the flexible wiring board 30 is extended upward and exposed from the upper surface of the head module 10.

  Thus, each head module 10 arranged in the head module placement hole 2a is in a state in which the terminal portion 31c of the flexible wiring board 30 is exposed, but the terminal portion 31c has a common wiring as shown in FIG. Since the portion has passed through the portion 31 b, the width is narrow even in a single-layer structure, and is arranged at a position shifted from the center of the flexible wiring board 30. Therefore, even if all the head modules 10 are arranged in the head module arrangement hole 2a, as shown in FIG. 9, the terminal portions 31c are shifted from each other between the head module rows 10a and interfere with each other. It does n’t fit.

  In addition, ink supply ports 42 are formed at both ends of each buffer tank 40. Ink is supplied into the buffer tank 40 from an ink cartridge (not shown) through the ink supply port 42. Furthermore, on the upper surface side of the buffer tank 40, a control board 4 (not shown) that is screwed into the screw hole 2b of the head frame 2 is disposed so as to cover all the buffer tanks 40.

FIG. 10 is a plan view showing the control board 4 in the line head 1 of the present embodiment.
The control board 4 shown in FIG. 10 is for controlling the ink discharge and the like of the line head 1, and on the control board 4, in addition to various capacitors, the terminal portion 31c of the flexible wiring board 30 shown in FIG. Is connected to the connector 4a. Further, a notch 4b for drawing out the terminal part 31c of the flexible wiring board 30 is formed in the vicinity of the connector 4a.

  Here, the connector 4a and the notch 4b are provided corresponding to the exposed terminal portion 31c of the flexible wiring board 30 shown in FIG. Therefore, in total, eight connectors 4a are sufficient for the two in-line × four-stage head modules 10, so that the necessary number of parts is reduced and the distance between the connectors 4a is widened. There are four notches 4b that are common to the two terminal portions 31c exposed adjacently, and two connectors 4a are arranged in a staggered manner toward each notch 4b.

  Further, the control substrate 4 is provided with an intermediate opening 4c and a connection port 4d at a portion facing the ink supply port 42 (see FIG. 9). Four intermediate openings 4c are formed corresponding to the central portion of the four-stage head module 10 (see FIG. 9), and the connection ports 4d correspond to both end portions of the four-stage head module 10. 4 (total 8) are formed. The control board 4 is screwed into the screw hole 2b of the head frame 2 in the state shown in FIG. 9 by the screw hole 4e.

FIG. 11 is a plan view showing the line head 1 of this embodiment, and is a view seen from the surface opposite to FIG.
As shown in FIG. 11, the control board 4 is screwed to the head frame 2 by screws 7. At this time, the terminal part 31c of the flexible flexible wiring board 30 passes through the cutout part 4b of the control board 4 and goes upward from the lower side of the control board 4, and as shown in the BB sectional view, It is bent at a right angle and connected to a connector 4a having an openable lid. Therefore, each head module 10 (see FIG. 9) is electrically connected to the control board 4 behind the flexible wiring board 30.

  Here, in each connector 4a to which the terminal portion 31c of each flexible wiring board 30 is connected, two connectors 4a are disposed in a staggered manner toward one notch portion 4b on both sides of each notch portion 4b. Yes. Therefore, as shown in FIG. 11, since the distance L between the connectors 4a is wide and the workability is improved, each terminal portion 31c is connected to each connector 4a in order to connect each terminal portion 31c to each notch portion 4b. The terminal portions 31c may be pinched one by one with a finger, bent, and inserted into the corresponding connector 4a. Then, one narrow terminal portion 31c is easily inserted into one connector 4a, and the connection of one head module 10 (see FIG. 9) is completed. The connection of each terminal portion 31c is not limited to the connector 4a, and may be soldering, crimping, or the like.

  Further, all the ink supply ports 42 of the buffer tank 40 shown in FIG. 9 are exposed to the outside without being hidden by the control substrate 4 due to the intermediate openings 4 c and the connection ports 4 d of the control substrate 4. For this reason, if both ends of the U-shaped tube 5 and one end of the ink supply pipe 6 are inserted into the ink supply port 42 from the outside of the control board 4 for each stage of the buffer tank 40, ink is supplied to the buffer tank 40 at each stage. Will be supplied. The two buffer tanks 40 connected in series are taken as one stage, and the horizontal width of the A4 recording paper is covered and arranged in four stages, so that Y (yellow), M (magenta) , C (cyan), and K (black), the line head 1 capable of ejecting four colors of ink.

  Thus, in the line head 1 of this embodiment, the flexible wiring board 30 is joined to the wiring board support portion 44 of the buffer tank 40 for each head module 10, and the common flow path forming portion 41 of the buffer tank 40 is connected. Cover the opening. As a result, a common ink flow path is formed between the flexible wiring board 30 and the common flow path forming portion 41. The head chip 20 is supported by the head chip support part 43 within the opening surface of the common flow path forming part 41. Therefore, the ink liquid chamber 26 of the head chip 20 communicates with the common flow path.

  Therefore, the head module 10 of the present embodiment can fix the head chip 20 directly to the buffer tank 40 without using a module frame that is necessary in the prior art. In addition, the common flow path can be formed by the flexible wiring board 30 without using a top plate that is necessary in the prior art. As a result, the head module 10 can be configured by only three parts of the head chip 20, the flexible wiring board 30, and the buffer tank 40, and the number of parts is reduced, so that the head module 10 and the line head 1 are produced. And assembly are greatly improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications as described below are possible, for example.
(1) In the present embodiment, the nozzle 25 a is formed in the nozzle formation layer 25 of the head chip 20, and the opening 30 a through which ink ejected from the nozzle 25 a can pass is formed in the connecting portion 30 a of the flexible wiring board 30. . However, instead of forming the nozzle 25 a on the head chip 20, the nozzle may be formed on the connecting portion 30 a of the flexible wiring board 30. In this case, the heating resistor 22 of the head chip 20 and the nozzle of the connecting portion 30a of the flexible wiring board 30 are opposed to each other.

  (2) In this embodiment, after fixing the head chip 20 and the flexible wiring board 30 so that the electrode 23 of the head chip 20 and the wiring 31 of the flexible wiring board 30 face each other, the inside of the opening surface of the buffer tank 40 Thus, the flexible wiring substrate 30 and the buffer tank 40 are connected so that the ink liquid chamber 26 of the head chip 20 communicates with the common flow path, and the flexible wiring substrate 30 covers the opening surface of the buffer tank 40 to form a common flow path. Fixed. However, the present invention is not limited to this, and after fixing the head chip 20 and the buffer tank 40 so that the ink liquid chamber 26 of the head chip 20 communicates with the common flow path within the opening surface of the buffer tank 40, the head chip 20 is fixed. The flexible wiring board 30 and the buffer tank 40 are fixed such that the electrode 23 of the flexible wiring board 30 and the wiring 31 of the flexible wiring board 30 face each other, and the flexible wiring board 30 covers the opening surface of the buffer tank 40 to form a common flow path. You may make it do.

FIG. 3 is a plan view showing the line head of the present embodiment, as viewed from the ink ejection surface side. It is a partial cross section perspective view which shows the head chip in the head module of this embodiment. It is a fragmentary perspective view which shows the connection relation of the head chip and flexible wiring board in the head module of this embodiment. It is a top view which shows the flexible wiring board in the head module of this embodiment, and is the figure seen from the ink discharge surface side. It is a top view which shows the wiring structure of the flexible wiring board in the head module of this embodiment. FIG. 4 is a plan view showing a buffer tank in the head module of the present embodiment, as viewed from the ink ejection surface side. FIG. 3 is a plan view showing the head module of the present embodiment, as viewed from the ink ejection surface side. It is a fragmentary sectional view showing the circumference of the head chip in the head module of this embodiment. It is a top view which shows the line head of the state which has arrange | positioned all the head modules of this embodiment to the head frame, and is the figure seen from the surface on the opposite side to FIG. It is a top view which shows the control board in the line head of this embodiment. It is a top view which shows the line head of this embodiment, and is the figure seen from the surface on the opposite side to FIG.

Explanation of symbols

1 Line head (liquid discharge head)
4 Control board 10 Head module 20 Head chip 20a Head chip array 22 Heating resistor (energy generating element)
23 Electrode 25a Nozzle 26 Ink liquid chamber (liquid chamber)
30 Flexible wiring board (wiring board)
30a Opening 31 Wiring 40 Buffer tank (common flow path member)
41 Common flow path forming part 43 Head chip support part 44 Wiring board support part

Claims (12)

A plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and electrodes for electrically connecting the energy generating elements and the control substrate are provided. A provided head chip;
A wiring board having wiring for electrically connecting the electrodes of the head chip and the control board;
A common flow path member for forming a common flow path communicating with all the liquid chambers of the head chip,
A head module that drives each energy generating element of the head chip via the wiring board and discharges the liquid in each liquid chamber by applying a discharge force to the liquid in each liquid chamber;
The common flow path member is
A hollow common flow path forming part that opens on one side,
A head chip support part for supporting the head chip within the opening surface of the common flow path forming part;
A wiring board support part for supporting the wiring board covering the opening surface of the common flow path forming part,
The head chip is supported by the head chip support portion so that each of the liquid chambers and the common channel communicate with each other.
The wiring board is
A connecting portion for connecting the wiring to the electrode;
A common wiring portion that summarizes the plurality of wirings common to the head chip;
A terminal portion for connecting the wiring to the control board;
A connecting part for connecting the two common wiring parts;
The connecting portion, the terminal portion, and the connecting portion, each of the wirings is constituted by a single layer, and the common wiring portion is constituted by a plurality of layers of each of the wirings , The head module is supported by the wiring board support portion so as to form the common flow path therebetween. The head module according to claim 1,
A plurality of head chip rows in which a plurality of head chips are arranged in one direction are provided,
A head module, wherein a plurality of the head chip support portions of the common flow path member are provided corresponding to each of the head chips in each of the head chip rows. The head module according to claim 1,
The head chip has a nozzle for discharging a liquid so as to face the energy generating element,
The wiring module is provided with an opening through which liquid ejected from the nozzle can pass. The head module according to claim 1,
The wiring module is provided with a nozzle for discharging a liquid so as to face the energy generating element of the head chip. The head module according to claim 1,
The wiring board is flexible. A head module. Multiple head modules;
A control board for controlling each of the head modules,
Each of the head modules
A plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and electrodes for electrically connecting each of the energy generating elements and the control substrate A head chip provided with
A wiring board having wiring for electrically connecting the electrodes of the head chip and the control board;
A common flow path member for forming a common flow path communicating with all the liquid chambers of the head chip,
A liquid discharge head that drives each energy generating element of the head chip via the wiring substrate and discharges the liquid in each liquid chamber by applying a discharge force to the liquid in each liquid chamber;
The common flow path member is
A hollow common flow path forming part that opens on one side,
A head chip support part for supporting the head chip within the opening surface of the common flow path forming part;
A wiring board support part for supporting the wiring board covering the opening surface of the common flow path forming part,
The head chip is supported by the head chip support portion so that each of the liquid chambers and the common channel communicate with each other.
The wiring board is
A connecting portion for connecting the wiring to the electrode;
A common wiring portion that summarizes the plurality of wirings common to the head chip;
A terminal portion for connecting the wiring to the control board;
A connecting part for connecting the two common wiring parts;
The connecting portion, the terminal portion, and the connecting portion, each of the wirings is constituted by a single layer, and the common wiring portion is constituted by a plurality of layers of each of the wirings , The liquid discharge head is supported by the wiring board support portion so as to form the common flow path therebetween. Multiple head modules;
A control board for controlling each of the head modules,
Each of the head modules
A plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and electrodes for electrically connecting each of the energy generating elements and the control substrate A head chip provided with
A wiring board having wiring for electrically connecting the electrodes of the head chip and the control board;
A common flow path member for forming a common flow path communicating with all the liquid chambers of the head chip,
A liquid ejecting apparatus that ejects the liquid in each liquid chamber by driving each energy generating element of the head chip via the wiring substrate and applying a ejection force to the liquid in each liquid chamber;
The common flow path member is
A hollow common flow path forming part that opens on one side,
A head chip support part for supporting the head chip within the opening surface of the common flow path forming part;
A wiring board support part for supporting the wiring board covering the opening surface of the common flow path forming part,
The head chip is supported by the head chip support portion so that each of the liquid chambers and the common channel communicate with each other.
The wiring board is
A connecting portion for connecting the wiring to the electrode;
A common wiring portion that summarizes the plurality of wirings common to the head chip;
A terminal portion for connecting the wiring to the control board;
A connecting part for connecting the two common wiring parts;
The connecting portion, the terminal portion, and the connecting portion, each of the wirings is constituted by a single layer, and the common wiring portion is constituted by a plurality of layers of each of the wirings , The liquid ejection device is supported by the wiring board support portion so as to form the common flow path between the two. A plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and electrodes for electrically connecting the energy generating elements and the control substrate are provided. A provided head chip;
A wiring board having wiring for electrically connecting the electrodes of the head chip and the control board;
A common flow path member for forming a common flow path communicating with all the liquid chambers of the head chip,
The wiring board is
A connecting portion for connecting the wiring to the electrode;
A common wiring portion that summarizes the plurality of wirings common to the head chip;
A terminal portion for connecting the wiring to the control board;
A connecting part for connecting the two common wiring parts;
The connecting portion, the terminal portion, and the connecting portion, each of the wirings is configured by a single layer, the common wiring unit, each of the wirings is configured by a plurality of layers,
A method of manufacturing a head module, wherein each energy generating element of the head chip is driven via the wiring substrate, and the liquid in each liquid chamber is discharged to discharge the liquid in each liquid chamber. ,
After fixing the head chip and the wiring board so that the electrode of the head chip and the wiring of the wiring board face each other,
Each of the liquid chambers of the head chip communicates with the common channel within the opening surface of the common channel member, and the wiring substrate covers the opening surface of the common channel member to form the common channel. Thus, the wiring board and the common flow path member are fixed. A method of manufacturing a head module, wherein: In the manufacturing method of the head module according to claim 8,
The wiring board includes a positioning mark for attaching the head chip. A method of manufacturing a head module. In the manufacturing method of the head module according to claim 8,
The method of manufacturing a head module, wherein the common flow path member includes a positioning mark for joining the wiring boards. In the manufacturing method of the head module according to claim 8,
The wiring board has an adhesive sheet that is melted by heat attached to the attachment position of the head chip,
A method of manufacturing a head module. A plurality of energy generating elements for discharging liquid are arranged, a liquid chamber is formed around each of the energy generating elements, and electrodes for electrically connecting the energy generating elements and the control substrate are provided. A provided head chip;
A wiring board having wiring for electrically connecting the electrodes of the head chip and the control board;
A common flow path member for forming a common flow path communicating with all the liquid chambers of the head chip,
The wiring board is
A connecting portion for connecting the wiring to the electrode;
A common wiring portion that summarizes the plurality of wirings common to the head chip;
A terminal portion for connecting the wiring to the control board;
A connecting part for connecting the two common wiring parts;
The connecting portion, the terminal portion, and the connecting portion, each of the wirings is configured by a single layer, the common wiring unit, each of the wirings is configured by a plurality of layers,
A method of manufacturing a head module, wherein each energy generating element of the head chip is driven via the wiring substrate, and the liquid in each liquid chamber is discharged to discharge the liquid in each liquid chamber. ,
After fixing the head chip and the common flow path member so that the liquid chambers of the head chip and the common flow path communicate with each other within the opening surface of the common flow path member,
The wiring substrate and the common flow are formed such that the electrode of the head chip and the wiring of the wiring substrate face each other, and the wiring substrate covers the opening surface of the common flow channel member to form the common flow channel. A method of manufacturing a head module, comprising fixing a road member.

Images