JP2007001192A - Manufacturing method for head module, manufacturing method for liquid delivering head, and manufacturing method for liquid delivering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce manufacturing costs and to smooth a nozzle surface. <P>SOLUTION: The manufacturing method comprises a first process of sticking each nozzle sheet 25 so that a nozzle 25a is positioned within a head chip stationing hole and covers a part of the region of the head chip stationing hole at one side face of a module frame 11 under a first temperature environment, a second process of sticking each head chip 20 to each head chip stationing hole from the other side face of the module frame 11 under a second temperature environment lower than the first temperature environment, a third process of attaching a flexible wiring board 3 to the face side of the module frame 11 where the nozzle sheet 25 is fitted so that an electrode of the flexible wiring board 3 and an electrode 23 of the head chip 20 are electrically connected with each other, and a fourth process of coating the nozzle sheet 25 stuck to the module frame 11 and an end part of the flexible wiring board 3 with a protecting cover 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  Conventionally, an ink jet printer has been known as an example of a liquid ejecting apparatus, and a head (liquid ejecting head) used in the ink jet printer or the like has a plurality of nozzles for ejecting ink on a rigid head frame. Further, a head chip having a barrier layer for forming a liquid chamber and an energy generating element (for example, a heating element) is disposed on the nozzle sheet. Then, the wiring substrate is connected to the head chip, and the energy generating element is driven by a command from the control unit of the printer to apply the ejection force to the ink in the liquid chamber, so that the ink in the liquid chamber is ejected from the nozzle to print. To do.

Various techniques relating to such a head have been disclosed. For example, Patent Document 1 and Patent Document 2 are examples thereof.
JP 2003-175609 A JP 2004-223878 A

  The heads of the above Patent Document 1 and Patent Document 2 have a structure in which a head chip side electrode and a wiring board side terminal are connected by a gold wire (bonding wire), and an opening window formed in a nozzle sheet. Wiring is performed by a bonding apparatus. The opening window is provided for the electrical connection work, and is arranged so that a gold wire can be passed from the front surface side of the nozzle sheet to the wiring substrate on the back surface side. If the opening window is left open, a large amount of ink or dust may enter during ink ejection or cleaning, which may cause problems due to short-circuiting of the electric circuit or contamination inside the device. Therefore, after wiring is completed, a method of sealing by enclosing the gold wire exposed from the opening window with a resin sealing agent is taken so that the opening window is closed and foreign matter does not enter inside. . In addition, if the opening window is closed with a resin sealant, the gold wire and its connection part are hardened with the resin sealant, so that not only foreign matter can be prevented from entering, but also the wire cannot be removed by vibration or impact. Protected.

  However, in order to achieve such electrical connection, the method of forming an opening window and sealing after wire bonding has a problem that the manufacturing process increases and the manufacturing cost increases. Another problem is that the resin sealant swells unevenly on the surface (nozzle surface) on the ink ejection side of the nozzle sheet, which is an obstacle when cleaning the nozzle surface.

As described above, the heads of Patent Document 1 and Patent Document 2 described above require a resin sealing process for fixing and protecting a wired gold wire as well as a wire bonding process. It has become. Ink jet printers mainly perform wiping of the nozzle surface as part of ejection recovery. In wiping, the nozzle surface is rubbed with a cleaning member such as a roller or blade to remove dirt adhering to the nozzle surface. Therefore, the nozzle surface should be as flat as possible so that the contact pressure of the cleaning member is uniform. It is desirable to be. However, in the heads of Patent Document 1 and Patent Document 2 described above, the resin sealant swells locally on the nozzle surface, causing the cleaning function to deteriorate.
Therefore, the problem to be solved by the present invention is to reduce the manufacturing cost and to smooth the nozzle surface.

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 for arranging the head chip therein are formed, and by applying an ejection force to the liquid in the liquid chamber by the energy generating element, A method of manufacturing a head module that discharges liquid in the liquid chamber from the nozzle, wherein the one surface of the module frame in a first temperature environment In the first step, the nozzle sheet is attached to each head chip arrangement hole so that the nozzle is located in the head chip arrangement hole and covers a part of the area of the head chip arrangement hole. And from the other surface of the module frame so that the energy generating element of the head chip and the nozzle are arranged in a position facing each other in a second temperature environment lower than the first temperature environment, The second step of attaching the head chip to each of the head chip arrangement holes, and the nozzle sheet of the module frame so that the electrode of the wiring board and the electrode of the head chip are electrically connected A third step of attaching the wiring board to the surface side provided with the nozzle sheet attached to the module frame and an end of the wiring board Characterized in that it comprises a fourth step of coating.

In the above invention, the head chip arrangement hole is formed in the module frame, and the nozzle sheet is attached so as to cover a part of each head chip arrangement hole under the first temperature environment. Then, in a second temperature environment lower than the first temperature environment, the head chip is stuck in the head chip placement hole from the surface opposite to the surface on which the nozzle sheet is stuck, and the nozzle sheet of the module frame is A wiring board is attached to the provided surface side, and the electrodes of the wiring board and the electrodes of the head chip are electrically connected. Therefore, when the head chip and the wiring board are electrically connected, the wire bonding process and the resin sealing process are not required.
After that, the nozzle sheet attached to the module frame and the end of the wiring board are covered. Therefore, the surface of the nozzle surface can be made smooth without any rise.

  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 method for manufacturing a head module of the present invention, the wire bonding step and the resin sealing step are not required when the head chip and the wiring substrate are electrically connected, and thus the manufacturing cost can be reduced. In addition, since the surface of the nozzle surface can be smooth without any local rise, damage to cleaning members such as rollers and blades can be prevented, the sealing performance of the head cap can be improved, and the performance of the head can be maintained. Function is improved. Furthermore, the wiring pattern cut surface of the wiring substrate is protected, and it is possible to prevent deterioration of recording quality and deterioration of cleaning performance due to non-uniformity of the wettability of the nozzle surface.

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 manufactured according to an embodiment of the present invention, as viewed from the liquid discharge surface side.
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 discharge head 1 includes a head frame 2 and a plurality of head modules 10 to which a flexible wiring board 3 is connected. In the plan view of FIG. 1, two head modules 10 are connected in series in the longitudinal direction in the head module arrangement hole 2a, and the two head modules 10 cover the length of the A4 width. One color is printed. 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. 2 is a cross-sectional view showing the periphery of one head chip 20 in the liquid ejection head 1 manufactured according to the embodiment of the present invention.
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. 3A is a plan view showing one module frame 11. The head module 10 manufactured according to this embodiment includes a module frame 11, eight head chips 20 and a nozzle sheet 25, and a buffer tank 12.

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 placement hole 11b has a hole shape slightly larger than the outer shape of the head chip 20, so that the head chip 20 can be completely placed inside.

  The module frame 11 is formed with two attachment holes 11d for fixing to the head frame 2. The attachment hole 11d is used when the head module 10 is attached to the head frame 2. Furthermore, a groove 11c (a hatched portion in FIG. 3A) is formed so as to surround a part of the outer edge portion of each head chip arrangement hole 11b.

FIG. 3 shows a process of attaching the nozzle sheet 25 to the module frame 11. As shown in FIG. 3, the adhesive 14 is applied (printed) to a region surrounded by the periphery of the head chip arrangement hole 11b and the groove 11c ((b) in the figure). The region of the adhesive 14 is formed in a size that substantially coincides with the outer edge portion of the nozzle sheet 25 when the nozzle sheet 25 is attached. The adhesive 14 is mixed with conductive particles as shown in FIG.
And after application | coating of the adhesive agent 14, the nozzle sheet 25 is stuck on the module frame 11 ((c) in a figure). 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 arrangement hole 11b, 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.

The nozzle 25a is formed by aligning the number of through-holes facing the number of heating resistors 22 in one head chip 20 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, And about 42.3 μm).

  Furthermore, in FIG. 3, the nozzle 25a row in each head chip arrangement hole 11b is a line connecting the nozzle 25a row in each head chip arrangement hole 11b (a line passing through the center of each nozzle 25a). The line is formed on the center line side of the module frame 11 drawn parallel to the longitudinal direction of the module frame 11. 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.

  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 bonded to the module frame 11 is in a tensioned state, so that the deflection of the nozzle sheet 25 can be prevented and flatness can be ensured.

  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.

  Furthermore, 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 concealed by the nozzle sheet 25 (see FIG. 2). Accordingly, the head chip 20 is formed so as to be electrically connected to the head chip 20 even after the head chip 20 is arranged in the head chip arrangement hole 11b.

  Subsequently, the electrode 23 provided on the head chip 20 side and the flexible wiring board 3 are joined (electrically connected). FIG. 4 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. 4, the front side is the sticking surface side of the nozzle sheet 25, but for the sake of easy understanding of the drawing, the head chip 20 attached from the opposite surface is shown by a solid line (hatched portion). Show. FIG. 5 is a perspective view showing the head chip 20, the nozzle sheet 25, and the flexible wiring board 3.

  As shown in FIG. 5, the flexible wiring board 3 is obtained by applying a wiring pattern 3a of copper foil to a flexible film-like substrate such as polyimide, and the copper foil is sandwiched from both sides with polyimide or the like. The so-called sandwich structure is formed by cutting into a desired shape. Then, as shown in FIG. 4, two flexible wiring boards 3 are attached to one head module 10. That is, four head chips 20 are arranged in two rows of four, but one flexible wiring board 3 is attached in each row, and each wiring pattern 3 a is bonded to the electrode 23 of the head chip 20. .

  At this time, the nozzle sheet 25 and the flexible wiring board 3 are adjacently bonded and fixed on the module frame 11 so that the electrodes 23 are not easily detached from each other. In the manufacturing process, since the cross section of each wiring pattern 3a is exposed, there is a risk of short circuit between the wiring patterns 3a when contacting the nozzle sheet 25. Therefore, the exposed surface (cross section) of the wiring pattern, which is the outer edge of the flexible wiring board 3, is brought close to the outer edge of the nozzle sheet 25, but with a slight gap between them, a conductive adhesive (see FIG. 2). ) To the module frame 11.

  In this state, as shown in FIG. 2, the electrode 23 of the head chip 20 and the flexible wiring board 3 are connected via the anisotropic conductive film 28 (ACF connection). By adopting this ACF connection, it becomes possible to eliminate the resin sealing process associated with fixing / protecting the wired gold wire as well as the wire bonding process that has been required so far. Moreover, the rise of the resin-sealed portion of wire bonding is eliminated.

  Therefore, although the manufacturing cost is reduced due to the effect of adopting the ACF connection and the nozzle surface can be made without the rise of the sealing resin, the nozzle sheet 25 and the flexible wiring board 3 are joined to one surface of the module frame 11. As shown in FIG. 5, strictly speaking, the nozzle surface has a step of tens of μm, which is the material thickness, at the ends of the nozzle sheet 25 and the flexible wiring board 3. Although this step is not as high as the resin-sealed part of wire bonding, the edge of the edge is an edge, and it is easy to get caught by the roller or blade that passes there during wiping during cleaning It has become. Therefore, not only the nozzle sheet 25 and the flexible wiring board 3 caught on the rollers and blades are peeled off from the module frame 11, but also the rollers and blades that have passed may be damaged.

  When the head does not operate, the nozzle surface is usually covered with a head cap (not shown). The head cap protects the nozzle surface and prevents the ink from drying. Some head caps are provided with an ink suction mechanism and a function of sucking ink to prevent clogging of the nozzle 25a. . In order to effectively draw out these functions, the head cap is formed of an elastic member such as rubber and is designed to maintain airtightness when the nozzle surface is covered. When you get on, it becomes a factor that impairs airtightness.

  Furthermore, in the structure in which the flexible wiring board 3 is bonded and fixed on the module frame 11, the wiring pattern 3 a on the side connected to the electrode 23 of the head chip 20 is exposed to the outside through a gap with the nozzle sheet 25. If conductive ink or dust adheres to it, there is a risk of short circuit.

  Furthermore, when the nozzle surface is formed by joining different materials such as the stainless steel module frame 11, the nickel nozzle sheet 25, and the polyimide flexible wiring board 3, the wettability varies depending on the material of each part. As a result, the surface state of each part changes even though it is on the same nozzle surface. When the difference in the wettability of the nozzle surface is large, the amount of ink adhering is biased, resulting in a partial ink pool. If there is a liquid pool of ink around the nozzle 25a, the flying direction of the ink will not be stable, and printed characters will be distorted or the image will be disturbed. . In addition, since the distribution of the adhering ink is not uniform, the degree of contamination varies and the cleaning performance is not stable.

  Thus, the nozzle sheet 25 and the end portions (steps on the nozzle surface) of the flexible wiring board 3 are harmful when cleaning or capping. In addition, a gap between the exposed surface (cross section) of the wiring pattern of the flexible wiring board 3 may cause a short circuit. Further, if the nozzle surface is made of a different material, the wettability is not uniform, and the ink discharge function and the cleaning function are deteriorated.

  Therefore, in order to eliminate the disadvantages associated with the configuration of the nozzle surface, a protective cover 30 is attached to the nozzle surface. FIG. 6 is a plan view showing a state in which the protective cover 30 is attached to the module frame 11, the nozzle sheet 25, and the flexible wiring board 3. As shown in FIG. 6, the protective cover 30 overlaps the module frame 11 with the nozzle sheet 25 in a portion excluding the periphery of the nozzle 25 a by the window portion 30 a, the module frame 11 in a portion excluding the periphery of the mounting hole 11 d, and the module frame 11. In this embodiment, a thermosetting adhesive is applied (printed) to a sticking surface of a polyimide film rich in heat resistance, insulation resistance, flexibility, etc. 2), and after being bonded onto the nozzle surface, it is cured by heating and bonded. The window 30a has a size that can remove the dirt on the nozzle surface during wiping, and has a substantially oval shape on which rollers and blades can easily ride.

  The protective cover 30 (adhered polyimide film) covers and protects the end portions of the nozzle sheet 25 and the flexible wiring board 3, covers the edges, and reduces the step on the nozzle surface. The gap between the outer edge and the outer edge of the nozzle sheet 25 is also covered. Therefore, the possibility that the nozzle sheet 25 and the flexible wiring board 3 may be caught by the roller or blade passing therethrough during the cleaning and peeling off, or conversely damaging the passed roller or blade, is eliminated, and the wiring pattern of the flexible wiring board 3 is eliminated. Short-circuiting of the exposed surface (cross section) is also eliminated. Further, since the step is relaxed to a gentle gradient, the head cap (not shown) has irregularities within a range that can be followed, and airtightness at the time of capping is ensured. Furthermore, since the surface other than the periphery of the nozzle 25a can be made of the same material (polyimide resin), the wettability of the nozzle surface can be made substantially uniform, the recording quality is improved, and the cleaning performance is stable. To do.

  Ink is used as an ink composition containing an ionic substance serving as a conductive agent so as to be effective for detecting the remaining amount of ink. Therefore, as shown in FIG. 2, the gap between the head chip 20 and the module frame 11 (opposite the flow path 27) is sealed with a resin 29 such as an epoxy resin so that the live part is not short-circuited by ink. Stopped.

Next, as shown in FIG. 2, the buffer tank 12 is bonded so as to cover the upper part of the head chip 20. The buffer tank 12 is a tank for temporarily storing ink, and one buffer tank 12 is provided for one head module 10. Further, the buffer tank 12 has substantially the same shape as the module frame 11 when viewed in a plan view. Then, as shown in FIG. 2, a hollow liquid flow path (a dot portion in FIG. 2) is formed inside the buffer tank 12. 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 forms a liquid flow path common to all the head chips 20 and temporarily stores ink to be supplied to the ink liquid chamber 26. In the present embodiment, the buffer tank 12 is particularly rigid for fixing the module frame 11. It is also a support member.

When the buffer tank 12 is mounted on the module frame 11, all the head chip arrangement holes 11b are covered. As shown in FIG. 2, 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.

  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.

Furthermore, in the present embodiment, one liquid discharge head 1 is formed by using a plurality of the head modules 10.
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 screwed and positioned.

  Although not shown, the buffer tanks 12 of the eight head modules 10 can be seen on the surface opposite to FIG. The buffer tanks 12 connected in series are connected by a U-shaped tube. Further, the connection side end portions of the two flexible wiring boards 3 with respect to one head module 10 extend perpendicular to the paper surface.

  Next, a control board for controlling the discharge of liquid and the like is screwed to the surface side where the buffer tank 12 is provided by screws. On the control board, in addition to various capacitors, a connector for connecting to the flexible wiring board 3 is provided. A notch is formed in the vicinity of the connector, and the tip of the flexible wiring board 3 passes from the lower side to the upper side through the notch and is connected to the connector on the control board. Has been.

  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.

FIG. 7 is a cross-sectional view showing the periphery of one head chip 20 in the liquid discharge head 1 manufactured according to another embodiment of the present invention. FIG. 8 is a plan view showing a state in which the protective cover 30 is formed on the module frame 11, the nozzle sheet 25, and the flexible wiring board 3.
In the embodiment shown in FIG. 7 and FIG. 8, a portion of the nozzle sheet 25 excluding the periphery of the nozzle 25 a, the exposed portion of the module frame 11, and the portion of the flexible wiring board 3 that overlaps the module frame 11 are made of resin layers. The protective cover 30 is formed by covering.

  The protective cover 30 is made of a thermosetting epoxy resin having excellent properties such as adhesiveness, toughness, heat resistance, electrical insulation, and corrosion resistance, and covers the entire discharge surface except for the periphery of the nozzle 25a. Further, it is applied on the nozzle surface by screen printing (silk printing) (shaded area in FIG. 8). By screen printing, it can apply | coat correctly so that the circumference | surroundings of the nozzle 25a may become the window part 30a. The applied epoxy resin is heated and cured, and the cured epoxy resin layer becomes the protective cover 30.

  The protective cover 30 (cured epoxy resin layer) covers and protects the end portions of the nozzle sheet 25 and the flexible wiring board 3, covers the edges, and relaxes the step on the nozzle surface. The gap between the outer edge and the outer edge of the nozzle sheet 25 is also covered. Therefore, the possibility that the nozzle sheet 25 and the flexible wiring board 3 may be caught by a roller or blade passing therethrough during the cleaning and peeling off, or conversely, the roller or blade passing therethrough may be damaged, and the wiring pattern of the flexible wiring board 3 is eliminated. Short-circuiting of the exposed surface (cross section) is also eliminated. Further, since the step is relaxed to a gentle gradient, the head cap (not shown) has irregularities within a range that can be followed, and airtightness at the time of capping is ensured. Furthermore, since the surface other than the periphery of the nozzle 25a can be made of the same material (epoxy resin), the wettability of the nozzle surface can be made substantially uniform, the recording quality is improved, and the cleaning performance is stable. To do.

  The resin forming the protective cover 30 may be a resin having heat resistance, ink resistance, etc., such as silicon resin and acrylic resin, in addition to polyimide resin and epoxy resin. In addition to thermosetting resins, UV curable resins can also be used.

  As described above, in the present embodiment, when the head chip 20 and the flexible wiring board 3 are electrically connected, the wire bonding process and the resin sealing process are not required, and thus the manufacturing cost can be reduced. Moreover, by covering the nozzle surface with the protective cover 30, it is possible to protect the end portion of the nozzle sheet 25 and the flexible wiring board 3 bonded to the nozzle surface, and to reduce the level difference. Therefore, damage to cleaning members such as rollers and blades is prevented, the sealing performance of the head cap is improved, and the performance maintaining function of the head is improved.

  Furthermore, since the end where the wiring pattern 3a of the flexible wiring board 3 is exposed is protected, a short circuit can be prevented without performing post-treatment such as resin sealing. In addition, since the wettability of the nozzle surface is made almost uniform by the protective cover 30, not only can the flying direction of the ink be stabilized, the distortion of characters and the disturbance of the image can be reduced, but also the distribution of ink stains adhering to the nozzle surface can be reduced. Uniformity and stable cleaning performance.

It is a top view which shows the liquid discharge head manufactured by one Embodiment of this invention, and is the figure seen from the liquid discharge surface side. FIG. 5 is a cross-sectional view showing the periphery of one head chip in a liquid ejection head manufactured according to an embodiment of the present invention. It is a top view which shows the manufacturing process of a head module. 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 perspective view which shows a head chip, a nozzle sheet, and a flexible wiring board. It is a top view which shows the state which affixed the protective cover on the module frame, the nozzle sheet | seat, and the flexible wiring board. FIG. 6 is a cross-sectional view showing the periphery of one head chip in a liquid ejection head manufactured according to another embodiment of the present invention. It is a top view which shows the state which formed the protective cover in the module frame, the nozzle sheet | seat, and the 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 | positioning hole 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 30 Protective cover 30a Window

Claims (6)

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 having a plurality of head chip arrangement holes for arranging the head chip therein,
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,
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 chip placement 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 covering an end portion of the nozzle sheet and the wiring board attached to the module frame. In the manufacturing method of the head module according to claim 1,
In the fourth step, the nozzle sheet in a portion excluding the periphery of the nozzle, the module frame on the surface side to which the nozzle sheet is attached, and the wiring board in a portion overlapping the module frame are A method of manufacturing a head module, comprising: attaching a resin film coated with an adhesive to the side surface. In the manufacturing method of the head module according to claim 1,
In the fourth step, a resin is applied to a portion of the nozzle sheet excluding the periphery of the nozzle, the module frame on the surface side to which the nozzle sheet is attached, and the wiring board in a portion overlapping the module frame. A method of manufacturing a head module, comprising applying a material. In the manufacturing method of the head module according to claim 1,
Fifth step of attaching a tank that covers all the head chip placement holes and communicates with the liquid chambers of all the head chips 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,
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 chip placement 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;
A fourth step of covering the nozzle sheet attached to the module frame and an end of the wiring board;
A fifth step of attaching the tank to the surface side opposite to the surface of the module frame on which the nozzle sheet is attached;
And a sixth step of housing a plurality of the head modules in the head module arrangement hole of the head frame. 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 ejection apparatus that ejects 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,
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 chip placement 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;
A fourth step of covering the nozzle sheet attached to the module frame and an end of the wiring board;
A fifth step of attaching the tank to the surface side opposite to the surface of the module frame on which the nozzle sheet is attached;
And a sixth step of housing a plurality of the head modules in the head module arrangement hole of the head frame.

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