JP2007015216A - Head module, liquid discharging head, liquid discharging device, manufacturing method of head module, and manufacturing method of liquid discharging head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a warpage or a distortion from occurring on a module frame, to increase the planar property and the assembly precision of an ink discharging surface, and at the same time, to reduce the manufacturing cost. <P>SOLUTION: A head chip arranging hole 11b of the module frame 11 is formed by an etching process. A nozzle seat 25 is respectively arranged in such a manner that on one side surface of the module frame 11, a nozzle 25a may be positioned in the head chip arranging hole 11b to each head chip arranging hole 11b, and a part of the region of the head chip arranging hole 11b may be covered. At the same time, the nozzle seat 25 is formed into a size which covers a part of the region of the head chip arranging hole 11b. The head chip is respectively arranged in each head chip arranging hole 11b from the other side surface of the module frame 11 in such a manner that a heating resistor and the nozzle 25a may be arranged at confronted positions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a head module that constitutes a part of a head for discharging a liquid, a liquid discharge head and a liquid discharge apparatus using the head module, and a method for manufacturing the head module and the liquid discharge head. Specifically, the present invention relates to a technique related to improvement in flatness and assembly accuracy of a liquid discharge surface.

  2. Description of the Related Art Conventionally, as an example of a liquid ejecting apparatus, a line head type ink jet printer in which nozzles for ejecting ink are arranged in a length corresponding to the width of a recording sheet is known. The head (liquid discharge head) used in this line printer supports one nozzle sheet on a rigid head frame, and further, on the nozzle sheet, a heating resistor (energy generating element) and a surrounding of the heating resistor Further, a head chip including a barrier layer for forming a liquid chamber is accurately arranged corresponding to each line.

Such a line printer does not require a means for moving the head in the main scanning direction, so that vibration and noise are reduced, and the printing speed can be significantly increased.
However, on the other hand, if any part of the whole head is defective due to partial damage of the nozzle sheet or defective head chip, it is treated as a defective product, and as a result, quality control becomes difficult and excellent in mass productivity. I could not say. Further, even if the head is partially broken, the entire head must be replaced, which is inefficient and requires expensive repair costs.

Therefore, a modular head in which a plurality of head modules are combined has been proposed, and various techniques have been disclosed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).
Japanese Patent No. 3437963 Japanese Patent No. 3459129 JP 2002-86735 A

  By adopting these technologies, 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 of the head and an accompanying increase in mass productivity. Also, in terms of service, it is efficient and user-friendly because only the defective head module needs to be replaced. Furthermore, by changing the arrangement and combination of the head modules, it becomes possible to easily provide heads of various sizes, and efficient design and manufacture can be expected.

  Here, in the modular heads described in Patent Document 1, Patent Document 2, and Patent Document 3, the ink discharge surface is flat so that the nozzle arrangement is not displaced. Thus, it is necessary to accurately arrange each head module. In other words, if the nozzle arrangement of each head module is misaligned or the flatness of the ink ejection surface cannot be maintained, it becomes a fatal defect and satisfactory ejection performance cannot be obtained.

  In more detail in this regard, although the structure of the head module cannot be generally defined, generally a rigid module frame such as metal or plastic, a small nozzle sheet for the module, and a corresponding head chip A predetermined number of each member is incorporated. That is, the module frame has a plurality of head chip arrangement holes for arranging the head chips therein, and the module frame has a predetermined rigidity after the plurality of head chip arrangement holes are formed. Must be. Therefore, considering the material characteristics and versatility, it is practical and practical to form the module frame from a metal plate. The accuracy of the module frame affects the flatness of the ink ejection surface, and the accuracy of the head chip mounting hole affects the accuracy of the head chip mounting hole.

As a method of processing the metal plate to form a module frame and forming the head chip arrangement hole, there are cutting, pressing, laser processing and the like.
However, cutting such as milling has a high processing cost and has problems such as deformation due to processing strain and generation of burrs. Also in the press working, there is a problem that warpage and distortion occur as in the cutting work, and burrs occur at the cut edges such as the head chip placement holes. Furthermore, laser processing has problems such as generation of smear due to thermal processing, generation of processing distortion, and roughness of the processed surface.

Therefore, it is difficult to use the module frame manufactured by these processing methods as it is, and correction / correction in several steps such as correction processing and polishing processing is required. In addition, because the finish varies depending on the setting conditions of the processing machine, such as press pressure in the press, adjustment of mold attachment, laser output in the laser processing machine, etc., along with close control of those, correction and correction processes according to the change However, neither of them can be easily done and the cost is high.
Therefore, the problem to be solved by the present invention is to prevent warpage and distortion of the module frame, to improve the flatness of the ink ejection surface and the assembly accuracy, and to reduce the manufacturing cost.

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 are arranged substantially linearly at a constant interval on a semiconductor substrate, and the energy generating element is provided on a surface provided with the energy generating elements. A head chip provided with a barrier layer for forming a liquid chamber around the element and an electrode for electrical connection to the outside, a nozzle sheet on which a nozzle is formed, and the electrode of the head chip electrically A wiring board to be connected; and a module frame in which a plurality of head chip arrangement holes, which are holes for arranging the head chips therein and are slightly larger than the outer shape of the head chip, are formed by the energy generating element. A head module that discharges liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber. The head chip arrangement hole of the frame is formed by etching, and the nozzle sheet is positioned in the head chip arrangement hole with respect to each head chip arrangement hole on one surface of the module frame. Each of the head chip placement holes is arranged to cover a part of the head chip placement hole, and the head chip is formed to have a size covering a part of the head chip placement hole. The head arranged in each of the head chip arrangement holes from the other surface of the module frame so that the energy generating element and the nozzle are opposed to each other, and arranged in the head chip arrangement hole The electrode of the chip is a region not covered by the nozzle sheet of the head chip arrangement hole. The wiring board is exposed, and the electrode of the wiring board and the electrode of the head chip are electrically connected, and the head chip is exposed on the side of the module frame where the nozzle sheet is provided. It arrange | positions so that the said electrode which is carrying out may be covered.

In the above invention, a plurality of head chip arrangement holes are formed in the module frame, and each head chip arrangement hole is formed by etching. Then, the head chip is arranged in the head chip arrangement hole from the surface opposite to the surface on which the nozzle sheet is provided, and the energy generating element of the head chip and the nozzle of the nozzle sheet face each other. In this state, the wiring board is disposed on the nozzle sheet side.
Therefore, warp and distortion generated by press working or the like are eliminated, and the nozzle sheet and the wiring board can be accurately arranged in the module frame, and the head chip can be accurately arranged in the head chip arrangement hole.

  The energy generating element of the present invention may be a heating resistor (heating element) such as a heater, a piezoelectric element such as a piezo element, MEMS, or the like, but in the following embodiments, a thermal heating resistor is used. The body 22 corresponds. In the embodiment, the module frame 11 is provided with eight head chip placement holes 11 b, and one head module 10 is provided with eight head chips 20. Then, two head modules 10 are connected in series to form a line head (length of A4 plate), and four rows are provided, and Y (yellow), M (magenta), C (cyan), and A liquid discharge head 1 which is a color line head of four colors of K (black) is formed.

  According to the head module of the present invention, since the nozzle sheet can be accurately arranged on the module frame, the flatness of the ink ejection surface can be ensured. In addition, since the head chip can be accurately placed in the head chip placement hole, the assembly accuracy can be improved. Furthermore, since correction and correction such as correction processing and polishing processing of the module frame are not required by the etching process, the manufacturing cost can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a liquid discharge head 1 according to an embodiment of the present invention, as viewed from the liquid discharge surface side. FIG. 2 is a view as seen from the opposite side of FIG. FIG. 3 is a diagram in which the control board 4 is arranged on the front side of FIG.

  The liquid discharge head 1 is used as a head mounted on a liquid discharge apparatus (in this embodiment, a color line inkjet printer). As shown in FIG. 1, the liquid ejection head 1 includes a head frame 2, a flexible wiring board 3, and a plurality of head modules 10. In the plan view of FIG. 1, two head modules 10 are connected in series in the longitudinal direction, and the two head modules 10 cover one A4 width and print one color. . The two head modules 10 connected in series are provided in four rows to form a liquid ejection head 1 of four colors (Y, M, C, and K).

Further, eight head chips 20 are provided in each head module 10. FIG. 4 is a cross-sectional view showing the periphery of one head chip 20.
The head chip 20 includes a semiconductor substrate 21 made of silicon or the like, and a heating resistor 22 (corresponding to an energy generating element in the present invention) deposited on one surface of the semiconductor substrate 21. An electrode 23 is formed on the edge of the semiconductor substrate 21 that is on the same side as the surface on which the heating resistor 22 is formed and opposite to the edge on which the heating resistor 22 is formed. The heating resistor 22 and the electrode 23 are connected via a conductor portion (not shown) formed on the semiconductor substrate 21.

  A barrier layer 24 and a nozzle sheet 25 are laminated on the surface of the head chip 20 on which the heating resistor 22 is formed. The barrier layer 24 forms a side wall of the ink liquid chamber (pressurizing chamber) 26 and serves to bond a head chip 20 and a nozzle sheet 25 described later. The barrier layer 24 is made of, for example, a photosensitive cyclized rubber resist or an exposure curable dry film resist, and is laminated on the entire surface of the semiconductor chip 21 of the head chip 20 on which the heating resistor 22 is formed, and then the photolithography process. Thus, an unnecessary portion is removed by the above. Further, the barrier layer 24 is formed in a substantially concave shape when viewed in plan so as to surround the vicinity of the three sides of the heating resistor 22.

  Furthermore, the nozzle sheet 25 is formed with a plurality of nozzles 25a, for example, formed by an electroforming technique using nickel. In the nozzle sheet 25, more specifically, the central axis of the nozzle 25a and the heat generation so that the position of the nozzle 25a matches the position of the heating resistor 22, that is, the nozzle 25a faces the heating resistor 22. The resistor 22 is bonded to the barrier layer 24 so that the center of the resistor 22 coincides with the plan view.

  The ink liquid chamber 26 is composed of the semiconductor substrate 21, the barrier layer 24, and the nozzle sheet 25 so as to surround the heating resistor 22. The ink liquid chamber 26 is filled with the ink to be ejected, and the ink is applied when the ink is ejected. It becomes a pressure chamber. The surface of the semiconductor substrate 21 on which the heat generating resistor 22 is formed constitutes the bottom wall of the ink liquid chamber 26, and the portion of the barrier layer 24 surrounding the heat generating resistor 22 in a substantially concave shape forms the side wall of the ink liquid chamber 26. The nozzle sheet 25 constitutes the top wall of the ink liquid chamber 26. The ink liquid chamber 26 communicates with a flow path 27 between the head chip 20 and the module frame 11 as shown in FIG.

  The one head chip 20 is usually provided with heating resistors 22 in units of 100, and each of the heating resistors 22 is uniquely selected by a command from a control unit (not shown) of the printer. The ink in the ink liquid chamber 26 corresponding to the heating resistor 22 can be ejected from the nozzle 25 a facing the ink liquid chamber 26.

  That is, when the ink liquid chamber 26 is filled with ink, the heating resistor 22 is rapidly heated by passing a pulse current through the heating resistor 22 for a short time, for example, 1 to 3 μsec. As a result, a gas-phase ink bubble is generated at a portion in contact with the heating resistor 22, and a certain volume of ink is pushed away (the ink boils) due to the expansion of the ink bubble. As a result, ink having a volume equivalent to the pushed ink in the portion in contact with the nozzle 25a is ejected from the nozzle 25a as an ink droplet. The droplets are landed on the photographic paper to form dots (pixels).

Next, a more detailed structure and manufacturing process of the head module 10 will be described.
FIG. 5 is a plan view illustrating the module frame 11, and is a diagram illustrating a process of attaching the nozzle sheet 25 to the module frame 11. 6 is a perspective view and a sectional view showing a part of the manufacturing process of the module frame 11. FIG. 7 is a perspective view and a sectional view showing the manufacturing process of the module frame 11 following FIG.

As shown in FIG. 5, the module frame 11 is formed in a substantially rectangular shape when viewed in a plan view, and has engaging portions 11a cut out in a substantially L shape on both left and right ends.
The module frame 11 is made of, for example, stainless steel and has a thickness of about 0.5 mm. In this embodiment, substantially rectangular head chip arrangement holes 11b are formed at eight locations. The head chip arrangement hole 11b has a hole shape slightly larger than the outer shape of the head chip 20 (see FIG. 4), so that the head chip 20 can be completely arranged inside.

  The module frame 11 is formed with two mounting holes 11d for fixing to the head frame 2 with screws. The attachment hole 11d is used when the head module 10 is attached to the head frame 2 (see FIG. 1). Furthermore, a groove 11c (a hatched portion in FIG. 5A) is formed so as to surround a part of the outer edge portion of each head chip arrangement hole 11b. Such a module frame 11 is formed by etching a stainless steel plate.

  In the etching process, as shown in FIG. 6, first, a base material degreasing cleaning (FIG. 6A) is performed to remove oil, dirt, deposits, and the like on the surface of the base material (stainless steel plate) to be the module frame 11. . Next, a resist photosensitive film coating (FIG. 6B) is performed to uniformly apply a resist photosensitive film to both the front and back surfaces of the base material. Subsequently, using the mask on which the pattern of the module frame 11 is formed, pattern exposure (FIG. 6C) is performed to expose both the front and back surfaces of the base material coated with the resist photosensitive film at the same time. Transfer to the resist photosensitive film on the material. Thereafter, removal of the unexposed film and hardening of the photosensitive film (FIG. 6D) are performed. That is, the resist photosensitive film is removed (developed) from an unexposed portion on the pattern-exposed base material to expose the portion of the base material. In addition, the resist photosensitive film in the exposed portion is hardened by heating to give durability against the corrosive liquid.

  Then, as shown in FIG. 7, etching (FIG. 7 (e)) is performed to inject a corrosive liquid onto both the front and back surfaces of the base material. Then, the portion corresponding to the head chip arrangement hole 11b where the base material is exposed and the portion corresponding to the attachment hole 11d are subjected to corrosion processing and penetrate. Further, the portion corresponding to the mounting hole 11d is largely corroded on the screw head side, and becomes a counterbore portion described later. On the other hand, in the portion corresponding to the groove 11c, only the surface side of the base material is subjected to corrosion processing (half etching process). This etching can also be performed by dipping the base material in a corrosive solution.

  Next, the resist photosensitive film is removed and washed (FIG. 7F), and then the base material is cut (FIG. 7G). As a result, the module frame 11 is formed in which the head chip arrangement hole 11b, the attachment hole 11d having a countersink portion, and the groove 11c are formed. The counterbored portion of the mounting hole 11d is large enough to accommodate the head of the screw for fixing the module frame 11 to the head frame 2 (see FIG. 1), and the screw protrudes from the surface of the module frame 11. There is nothing.

  Such etching is born from the application of precision photography and photo-corrosion method, and is formed by chemical reaction. Therefore, it does not apply mechanical stress to the material as in press processing. It can be finished in the desired shape without any warpage, distortion, or burring caused by machining or laser machining.

  The etching process is also characterized by high processing accuracy. That is, when the plate material is etched from both sides, it can be processed with a dimensional accuracy of about ± 10% of the plate thickness. In the present embodiment, as described above, stainless steel with a plate thickness of 0.5 mm is used as the material of the module frame 11, and the outer dimensional accuracy can be processed within ± 0.05 mm. The etching process is so-called photolithography using a photographic original plate, and the accuracy within ± 0.05 mm is the same for a length of 10 mm and 100 mm. Furthermore, the dimension between the centers of the head chip arrangement hole 11b and the mounting hole 11d is theoretically zero error, and can actually be about ± 0.005 mm. In addition, if a plurality of the same patterns are prepared on the photographic original, a plurality of module frames 11 can be formed by one etching process, and the mass productivity is high.

  As shown in FIG. 5, a nozzle sheet 25 is attached to the module frame 11 formed in this way. That is, as shown in FIG. 5B, the adhesive 14 is applied (printed) to a region surrounded by the periphery of the head chip arrangement hole 11b and the groove 11c. The application area of the adhesive 14 has a size that substantially matches the outer edge of the nozzle sheet 25 when the nozzle sheet 25 is applied. And after application | coating of the adhesive agent 14, as shown in FIG.5 (c), the nozzle sheet | seat 25 is stuck on the module frame 11. As shown in FIG. At this time, excess adhesive 14 enters the groove 11c and is absorbed by the groove 11c.

  Further, the nozzle sheet 25 is stuck so as to cover a part of the area of the head chip arrangement hole 11b. Furthermore, the nozzle sheet 25 is formed in the minimum necessary size to be supported by the module frame 11, and when the nozzle sheet 25 is stuck on the head chip placement hole 11c, the nozzle sheet 25 is formed. Is formed in a size that exists only in the application range of the head chip arrangement hole 11b and the adhesive 14. That is, the nozzle sheet 25 is formed in the minimum necessary size so as to cover a necessary part of the region of the head chip arrangement hole 11b and to have a minimum adhesion area.

  Further, in the present embodiment, the nozzle sheet 25 is bonded to the module frame 11 by hot pressing by hot pressing. This joining is performed at the highest temperature (for example, about 150 ° C. under the first temperature environment in the present invention) in the manufacturing process of the head module 10 and the liquid discharge head 1. When the module frame 11 and the nozzle sheet 25 are compared, the nozzle sheet 25 has a larger coefficient of linear expansion (easily expands and contracts due to temperature changes). Below this temperature, the nozzle sheet 25 is stretched by the module frame 11.

That is, the expansion and contraction due to the temperature change of the nozzle sheet 25 is governed by the module frame 11 after the nozzle sheet 25 and the module frame 11 are joined.
Therefore, in order to ensure the rigidity of the module frame 11 as much as possible, it is preferable that the opening area of the head chip arrangement hole 11b of the module frame 11 is minimized. Therefore, the head chip arrangement hole 11 b has an outer shape slightly larger than the head chip 20.

Further, the module frame 11 to which the nozzle sheet 25 is joined must have a good flatness so that the nozzle sheet 25 can be securely attached to an accurate position.
In the present embodiment, since the head chip arrangement hole 11b of the module frame 11 is formed by etching, the module frame 11 has no warp, distortion, or cut edge.

  That is, when the head chip arrangement hole 11b of the module frame 11 is formed by press working, warpage, distortion, and cut edge are generated. For this reason, it is necessary to correct the warpage, distortion, and cut edge by performing a correction process or a polishing process after pressing. However, it is not efficient because a separate process such as a correction process and a polishing process is required. In addition, the correction treatment must be pressurized in consideration of the spring back of the base material, and is not easy, and the physical burden on the base material is large. Further, since the polishing process generates chips, if the removal is not complete, there is a risk of clogging of the nozzles and short circuiting of the electric wiring, which requires careful consideration.

  In the module frame 11 of the present embodiment, the quality troubles related to the module frame 11 are eliminated by forming the head chip arrangement holes 11b by etching. Further, as compared with the press working, a press die is not required, so that it is possible to shorten the manufacturing period related to the press die and reduce the cost.

  In the module frame 11 of the present embodiment having good flatness, the nozzle sheet 25 is securely attached at an accurate position, and as shown in FIG. 5C, the nozzle 25a row in each head chip arrangement hole 11b is arranged. The center of the module frame 11 drawn in parallel with the longitudinal direction of the module frame 11 when a line connecting the nozzles 25a in each head chip arrangement hole 11b (a line passing through the center of each nozzle 25a) is considered. It is formed on the line side. Further, when the head chip arrangement holes 11b are “N1”, “N2”, “N3”,..., “N8” in order from the left side, “N1”, “N3”, “N5” and “N7” The nozzle 25a row in the “th” head chip arrangement hole 11b is formed so as to be aligned on a straight line parallel to the center line. The same applies to the “N2”, “N4”, “N6” and “N8” -th relationships.

Therefore, the nozzle 25a rows in the adjacent head chip arrangement holes 11b, for example, the nozzle 25a rows in the “N1” -th and “N2” -th head chip arrangement holes 11b are on two straight lines parallel to the center line. Align.
In the present embodiment, eight head chip arrangement holes 11b are formed for one module frame 11, but the above relationship is satisfied even when more or fewer head chip arrangement holes 11b are formed. Like that.

The nozzle 25a is obtained by aligning the number of through holes corresponding to the number of the heating resistors 22 in one head chip 20 shown in FIG. 4 in one direction.
The nozzle 25a is formed by an excimer laser. Further, since the nozzle 25a formed by the laser beam is tapered, the laser beam is irradiated from the module frame 11 side to form the nozzle 25a. Thus, the nozzle 25a becomes a hole having a taper so that the opening diameter gradually decreases as it approaches the ink ejection surface (the outer surface of the nozzle sheet 25).

  Further, the pitch between the nozzles 25a of the nozzle 25a row located in each head chip arrangement hole 11b is the same as the arrangement pitch of the heating resistors 22 of the head chip 20 (when forming the head module 10 with a resolution of 600 dpi, (About 42.3 μm).

  Next, the head chip 20 in which the barrier layer 24 is laminated is arranged and fixed in each head chip arrangement hole 11b. This is performed in a second temperature environment lower than the first temperature environment (for example, at room temperature (about 25 ° C.)). Thereby, the barrier layer 24 and the nozzle sheet 25 are adhered. Here, the head chip 20 is thermocompression bonded while being aligned using a chip mounter. Further, in this case, thermocompression bonding is performed with an accuracy of, for example, about ± 1 μm so that the nozzle 25a is positioned directly below the heating resistor 22 of the head chip 20.

  By the way, when the head chip 20 and the nozzle sheet 25 are compared, the nozzle sheet 25 has a larger linear expansion coefficient. The thermocompression bonding temperature of the head chip 20 is lower than the bonding temperature between the module frame 11 and the nozzle sheet 25. Therefore, when the head chip 20 is thermocompression bonded, the nozzle sheet 25 that is securely bonded to the module frame 11 at an accurate position is in a tensioned state, so that the deflection of the nozzle sheet 25 can be prevented and flattened. Sex can be secured.

  Thus, when the head chip 20 on which the barrier layer 24 is formed is arranged in the head chip arrangement hole 11b and the nozzle sheet 25 and the head chip 20 are bonded, the surface of the nozzle sheet 25 on the head chip 20 side, The ink liquid chamber 26 is formed as described above by the barrier layer 24 and the surface of the head chip 20 on which the heating resistor 22 is formed. In addition, the nozzle 25a faces the heating resistor 22 accurately. Furthermore, the flatness of the ink ejection surface is ensured.

  When the head chip 20 is attached to the nozzle sheet 25, the electrode 23 of the head chip 20 is exposed to the outside without being hidden by the nozzle sheet 25 (see FIG. 4). Therefore, the head chip 20 can be electrically connected even after the head chip 20 is arranged in the head chip arrangement hole 11b.

  Therefore, the electrode 23 provided on the head chip 20 side and the flexible wiring board 3 are joined (electrically connected). FIG. 8 is a plan view showing a state in which the flexible wiring board 3 is joined after the nozzle sheet 25 and the head chip 20 are attached to the module frame 11. In FIG. 8, the front side is the attachment surface side of the nozzle sheet 25, but the head chip 20 attached from the opposite surface is shown by a solid line (hatched portion) for easy understanding of the drawing. Show.

  The flexible wiring board 3 has a so-called sandwich structure in which a copper foil is sandwiched from both sides with polyimide or the like. Two flexible wiring boards 3 are attached to one head module 10. The four head chips 20 are arranged in two rows by four, and one flexible wiring board 3 is attached to each row. A wiring pattern is formed on the flexible wiring board 3, and each wiring pattern is bonded to the electrode 23 of the head chip 20. At this time, the nozzle sheet 25 is attached so that the outer edge of the nozzle sheet 25 and the outer edge of the flexible wiring board 3 are close to each other.

Here, as shown in FIG. 4, the electrode 23 of the head chip 20 and the flexible wiring board 3 are connected via an anisotropic conductive film 28 (ACF connection).
After the connection, a resin 29 such as an epoxy resin is provided in the gap between the head chip 20 and the module frame 11 (opposite the flow path 27), and the anisotropic conductive film 28 is sealed. When the head module 10 is used, the periphery of the head chip 20 (upper side in FIG. 4) is soaked with ink so that the ink does not enter the live part and short-circuit. In addition, a gap is formed between the outer edge of the flexible wiring board 3 and the outer edge of the nozzle sheet 25. A resin 30 is provided from the nozzle sheet 25 side so as to fill the gap, and this gap is sealed.

Thus, after the nozzle sheet 25 and the head chip 20 are attached to the module frame 11, the flexible wiring board 3 is joined. Even if the nozzle sheet 25 and the flexible wiring board 3 can be accurately placed on the module frame 11 using the above, there is a high possibility that the nozzle sheet 25 and the flexible wiring board 3 may be misaligned or cause poor adhesion. In addition, when the module frame 11 has burrs, it not only causes adhesion failure but also damages the flexible wiring board 3 and may break the wiring pattern. Furthermore, since the flatness of the ink ejection surface cannot be maintained, the ejection performance is not uniform, and a maintenance mechanism such as a wiping device or a suction cap may not be able to fully perform its function. Then, when the module frame 11 is manufactured by cutting, pressing, or laser processing, the possibility of occurrence thereof increases.
However, since the module frame 11 of this embodiment is formed by etching and has no warp or distortion, such quality troubles do not occur.

Next, as shown in FIG. 4, the buffer tank 12 is bonded so as to cover the top of the head chip 20. FIG. 9 is a plan view showing a process of bonding the buffer tank 12, and FIG. 10 is a plan view showing the buffer tank 12 and the flexible wiring board 3.
The buffer tank 12 is a tank for temporarily storing ink, and one buffer tank 12 is provided for one head module 10.

  As shown in FIG. 10, the buffer tank 12 has substantially the same shape as the module frame 11 when viewed in a plan view. And as shown in FIG. 4, the inside of the buffer tank 12 forms the liquid flow path (the dot part in FIG. 4) which became the cavity. In particular, the buffer tank 12 of the present embodiment is formed such that the lower surface side (bonding surface side with the module frame 11) is opened, the side walls and the top wall are formed to have the same thickness, and the cross section is substantially reverse concave. Has been.

  The buffer tank 12 surrounds all the head chips 20 and the sealing material 29, forms a liquid flow path common to all the head chips 20, and temporarily stores the ink supplied to the ink liquid chamber 26. As shown in FIG. 9, after applying a thermosetting epoxy resin adhesive to the module frame 11, the adhesive is heated and cured with the buffer tank 12 positioned and fixed.

By the way, if the module frame 11 is warped or distorted, even if the buffer tank 12 can be accurately placed on the module frame 11 using a jig or the like during assembly, it will be misaligned or cause poor adhesion. The possibility increases. Incomplete joining of the buffer tank 12 causes ink leakage.
However, since the module frame 11 of the present embodiment is formed by etching and has no warp or distortion, such adhesion trouble does not occur. The module frame 11, the head chips 20, and the buffer tank 12 have the same linear expansion coefficient. This is because a large difference in coefficient of linear expansion causes troubles such as peeling of the adhesive due to the action of thermal stress, which is avoided.

  The buffer tank 12 is also a rigid support member for fixing the module frame 11 in the present embodiment. When the buffer tank 12 is mounted on the module frame 11, all the head chip arrangement holes 11b are provided. It comes to cover. As shown in FIG. 4, the inside of the buffer tank 12 and the ink liquid chamber 26 of each head chip 20 communicate with each other via a flow path 27 between the head chip placement hole 11 b and the head chip 20. Thereby, the buffer tank 12 forms a liquid flow path common to all the head chips 20 in the head module 10. Although not shown, a hole is formed in the top wall of the buffer tank 12, and ink is supplied into the buffer tank 12 from an ink tank (not shown) through this hole.

  As described above, one head module 10 includes the module frame 11, the eight head chips 20, the nozzle sheet 25, and the buffer tank 12. In this embodiment, a plurality of head modules 10 are used. Thus, one liquid discharge head 1 is formed.

  As shown in FIG. 1, a rigid head frame 2 is formed with a head module arrangement hole 2a. In this embodiment, eight head modules 10 are arranged side by side in the head module arrangement hole 2a. (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 positioned by being screwed to the rigid head frame 2 with screws 5.

Here, if the head of the screw 5 that fixes each head module 10 protrudes from the ink ejection surface, the blade may come into contact with the head of the screw 5 when wiping the ejection surface, or may be damaged during printing. Problems such as jamming due to contact of the recording paper occur.
However, in the module frame 11 of the present embodiment, as shown in FIG. 7, the attachment hole 11d having a countersink is formed by etching. Therefore, no distortion and burrs are generated as in cutting and pressing, and no post-processing is required, and the head of the screw 5 can be easily placed in the countersink. Therefore, the head of the screw 5 does not protrude from the ink ejection surface.

  As shown in FIG. 2, the buffer tanks 12 of the eight head modules 10 can be seen from the surface opposite to FIG. 1, and a U-shaped tube 13 is provided between the buffer tanks 12 connected in series. It is connected. Then, the connection side end portions (hatched portions in FIG. 2) of the two flexible wiring boards 3 extend perpendicularly to the paper surface with respect to one head module 10.

  In this state, as shown in FIG. 3, the control board 4 for controlling the ejection of ink and the like is screwed by screws 6 on the surface side where the buffer tank 12 is provided. On the control board 4, in addition to various capacitors, a connector 4a for connecting to the flexible wiring board 3 is provided. A notch 4b is formed in the vicinity of the connector 4a, and the leading end of the flexible flexible wiring board 3 passes from the lower side of the control board 4 through the notch 4b. And connected to the connector 4a of the control board 4. Therefore, each head module 10 is electrically connected to the control board 4 behind the flexible wiring board 3.

  In this way, two head modules 10 are connected in series to form an A4-compatible line head. Further, four rows of the head modules (consisting of two head modules 10) are arranged to form a color line head corresponding to four colors (colors) of Y, M, C, and K.

  As described above, in the present embodiment, the module frame 11 is manufactured by etching, so that processing with high accuracy and high productivity can be performed. Further, as compared with press working, a press die is not required, so that it is possible to shorten the manufacturing period and the cost related to the press die. Furthermore, the countersunk portion of the mounting hole 11d of the module frame 11 can be easily formed, and the head of the screw 5 can be prevented from protruding from the ink ejection surface. As a result, it is possible to wipe the ejection surface and feed the recording paper without any trouble.

  In addition, since the head module 10 can be assembled without the module frame 11 being warped, distorted, or broken, the mounting positions of the nozzle sheet 25, the flexible wiring board 3, and the buffer tank 12 can be accurately set. At the same time, it is securely fixed, and quality problems such as ink leakage and disconnection / short-circuiting of electrical wiring can be solved. Then, by assembling the individual head modules 10 without warping or distortion, the flatness of the entire ink ejection surface can be maintained even when the liquid ejection head 1 is formed, and a modular system that can fully exhibit the ejection function and maintenance function. A liquid ejection device can be provided.

FIG. 2 is a plan view showing a liquid discharge head according to an embodiment of the present invention, as viewed from the liquid discharge surface side. It is the figure seen from the surface on the opposite side to FIG. It is the figure which has arrange | positioned the printed circuit board in the front side of FIG. It is sectional drawing which shows the circumference | surroundings of one head chip. It is a top view which shows a module frame, and is a figure which shows the process of sticking a nozzle sheet | seat on a module frame. It is the perspective view and sectional drawing which show a part of manufacturing process of a module frame. FIG. 7 is a perspective view and a cross-sectional view showing a module frame manufacturing process following FIG. 6. It is a top view which shows the state which joined the flexible wiring board after the nozzle sheet and the head chip were affixed on the module frame. It is a top view which shows the process of adhere | attaching a buffer tank. It is a top view which shows a buffer tank and a flexible wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid discharge head 2 Head frame 2a Head module arrangement | positioning hole 3 Flexible wiring board (wiring board)
DESCRIPTION OF SYMBOLS 10 Head module 11 Module frame 11b Head chip arrangement hole 11d Mounting hole 12 Buffer tank (tank)
20 Head chip 21 Semiconductor substrate 22 Heating resistor (energy generating element)
23 Electrode 24 Barrier layer 25 Nozzle sheet 25a Nozzle 26 Ink liquid chamber (liquid chamber)

Claims (8)

A plurality of energy generating elements arranged on a semiconductor substrate in a substantially straight line at regular intervals, and a barrier layer for forming a liquid chamber around the energy generating elements on a surface provided with the energy generating elements; A head chip provided with electrodes for electrical connection with the outside;
A nozzle sheet on which nozzles are formed;
A wiring board electrically connected to the electrode of the head chip;
A module frame in which a plurality of head chip arrangement holes, each of which is a hole for arranging the head chip and is slightly larger than the outer shape of the head chip,
A head module that discharges the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
The head chip arrangement hole of the module frame is formed by etching,
The nozzle sheet is located on one side of the module frame so that the nozzle is positioned in the head chip arrangement hole and covers a part of the area of the head chip arrangement hole with respect to each head chip arrangement hole. And is formed in a size that covers a part of the area of the head chip arrangement hole,
The head chip is arranged in each of the head chip arrangement holes from the other surface of the module frame so that the energy generating element of the head chip and the nozzle are opposed to each other.
The electrode of the head chip arranged in the head chip arrangement hole is exposed from a region not covered by the nozzle sheet of the head chip arrangement hole,
In the wiring board, the electrode of the wiring board and the electrode of the head chip are electrically connected, and the head chip is exposed on the side of the module frame where the nozzle sheet is provided. The head module is disposed so as to cover the electrode. The head module according to claim 1,
Provided on the surface of the module frame opposite to the surface on which the nozzle sheet is disposed so as to cover all the head chip disposition holes, and provided with tanks communicating with the liquid chambers of all the head chips. A head module characterized by Multiple head modules;
A head frame in which a head module arrangement hole that accommodates a plurality of the head modules is formed, and
The head module is
A plurality of energy generating elements arranged on a semiconductor substrate in a substantially straight line at regular intervals, and a barrier layer for forming a liquid chamber around the energy generating elements on a surface provided with the energy generating elements; A head chip provided with electrodes for electrical connection with the outside;
A nozzle sheet on which nozzles are formed;
A wiring board electrically connected to the electrode of the head chip;
A module frame in which a plurality of head chip arrangement holes, each of which is a hole for arranging the head chip and is slightly larger than the outer shape of the head chip,
A liquid discharge head that discharges the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
The head chip arrangement hole of the module frame is formed by etching,
The nozzle sheet is located on one side of the module frame so that the nozzle is positioned in the head chip arrangement hole and covers a part of the area of the head chip arrangement hole with respect to each head chip arrangement hole. And is formed in a size that covers a part of the area of the head chip arrangement hole,
The head chip is arranged in each of the head chip arrangement holes from the other surface of the module frame so that the energy generating element of the head chip and the nozzle are opposed to each other.
The electrode of the head chip arranged in the head chip arrangement hole is exposed from a region not covered by the nozzle sheet of the head chip arrangement hole,
In the wiring board, the electrode of the wiring board and the electrode of the head chip are electrically connected, and the head chip is exposed on the side of the module frame where the nozzle sheet is provided. A liquid discharge head, which is disposed so as to cover the electrode. The liquid ejection head according to claim 3,
The module frame of the head module has a mounting hole for screwing and fixing to the head frame,
The liquid ejection head, wherein the mounting hole is formed by etching. Multiple head modules;
A head frame in which a head module arrangement hole that accommodates a plurality of the head modules is formed, and
The head module is
A plurality of energy generating elements arranged on a semiconductor substrate in a substantially straight line at regular intervals, and a barrier layer for forming a liquid chamber around the energy generating elements on a surface provided with the energy generating elements; A head chip provided with electrodes for electrical connection with the outside;
A nozzle sheet on which nozzles are formed;
A wiring board electrically connected to the electrode of the head chip;
A module frame in which a plurality of head chip arrangement holes, each of which is a hole for arranging the head chip and is slightly larger than the outer shape of the head chip,
A liquid discharge device that discharges the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
The head chip arrangement hole of the module frame is formed by etching,
The nozzle sheet is located on one side of the module frame so that the nozzle is positioned in the head chip arrangement hole and covers a part of the area of the head chip arrangement hole with respect to each head chip arrangement hole. And is formed in a size that covers a part of the area of the head chip arrangement hole,
The head chip is arranged in each of the head chip arrangement holes from the other surface of the module frame so that the energy generating element of the head chip and the nozzle are opposed to each other.
The electrode of the head chip arranged in the head chip arrangement hole is exposed from a region not covered by the nozzle sheet of the head chip arrangement hole,
In the wiring board, the electrode of the wiring board and the electrode of the head chip are electrically connected, and the head chip is exposed on the side of the module frame where the nozzle sheet is provided. A liquid ejecting apparatus, wherein the liquid ejecting apparatus is disposed so as to cover the electrode. A plurality of energy generating elements arranged on a semiconductor substrate in a substantially straight line at regular intervals, and a barrier layer for forming a liquid chamber around the energy generating elements on a surface provided with the energy generating elements; A head chip provided with electrodes for electrical connection with the outside;
A nozzle sheet on which nozzles are formed;
A wiring board electrically connected to the electrode of the head chip;
A module frame in which a plurality of head chip arrangement holes, each of which is a hole for arranging the head chip and is slightly larger than the outer shape of the head chip,
A method of manufacturing a head module that discharges liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element,
A pre-process for forming the head chip placement hole of the module frame by etching;
Under the first temperature environment, on one surface of the module frame, with respect to each head chip arrangement hole, the nozzle is positioned in the head chip arrangement hole, and a part of the area of the head chip arrangement hole is formed. A first step of sticking the nozzle sheet to cover each;
From the surface on the other side of the module frame, the energy generating element and the nozzle of the head chip are arranged at positions facing each other under a second temperature environment lower than the first temperature environment. A second step of attaching the head chip to each of the head module arrangement holes;
And a third step of attaching the wiring board to the surface of the module frame on which the nozzle sheet is provided so that the electrode of the wiring board and the electrode of the head chip are electrically connected. A method for manufacturing a head module. In the manufacturing method of the head module according to claim 6,
A fourth step of attaching a tank communicating with the liquid chambers of all the head chips and covering all the head chip arrangement holes on the surface of the module frame opposite to the surface on which the nozzle sheet is adhered. A method for manufacturing a head module, comprising: Multiple head modules;
A head frame in which a head module arrangement hole that accommodates a plurality of the head modules is formed, and
The head module is
A plurality of energy generating elements arranged on a semiconductor substrate in a substantially straight line at regular intervals, and a barrier layer for forming a liquid chamber around the energy generating elements on a surface provided with the energy generating elements; A head chip provided with electrodes for electrical connection with the outside;
A nozzle sheet on which nozzles are formed;
A wiring board electrically connected to the electrode of the head chip;
A module frame in which a plurality of head chip placement holes which are holes for placing the head chips therein and are slightly larger than the outer shape of the head chip are formed;
A tank that is arranged to cover all the head chip arrangement holes and communicates with the liquid chambers of all the head chips;
A method of manufacturing a liquid discharge head that discharges liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element,
A pre-process for forming the head chip placement hole of the module frame by etching and forming an attachment hole for fixing the module frame to the head frame by etching; and
Under the first temperature environment, on one surface of the module frame, with respect to each head chip arrangement hole, the nozzle is positioned in the head chip arrangement hole, and a part of the area of the head chip arrangement hole is formed. A first step of sticking the nozzle sheet to cover each;
From the surface on the other side of the module frame, the energy generating element and the nozzle of the head chip are arranged at positions facing each other under a second temperature environment lower than the first temperature environment. A second step of attaching the head chip to each of the head module arrangement holes;
A third step of attaching the wiring board to the surface of the module frame on which the nozzle sheet is provided so that the electrode of the wiring board and the electrode of the head chip are electrically connected; and A fourth step of attaching the tank to the surface side opposite to the surface on which the nozzle sheet is adhered and making the head module;
A fifth step of accommodating a plurality of the head modules in the head module arrangement hole of the head frame, and screwing and fixing the module frames of the head modules to the head frame through the mounting holes; A method of manufacturing a liquid discharge head, comprising:

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