JP2007015123A - Head module, liquid ejecting head, liquid ejector, and manufacturing method for head module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an outflow of a sealing material at a connecting part, an exposure part and the like of a wiring board by a simple constitution. <P>SOLUTION: A nozzle sheet 25 is arranged to have nozzles positioned within a head chip stationing hole of a module frame 11 and to cover a part of the region of the head chip stationing hole. A head chip 20 has a pair of groove parts 24a formed in a barrier layer 24. Each head chip 20 is arranged at each head chip stationing hole so that a heating resistor 22 and the nozzle are opposed to each other and each groove part 24a is disposed on the nozzle sheet 25 at a position where the nozzles are not formed. A flexible wiring board 3 is arranged so that its electrode and an electrode of the head chip 20 are electrically connected to each other. A gap between the head chip 20 of the side where the flexible wiring board 3 is set and the module frame 11 is sealed by the sealing material 29. <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 of manufacturing the head module. More specifically, the present invention relates to a technique for preventing a liquid flow path from being blocked by a sealing material that seals a gap between a head chip and a module frame.

  2. Description of the Related Art Conventionally, an ink jet printer is known as an example of a liquid ejecting apparatus, and a head (liquid ejecting head) used in the ink jet printer or the like performs recording by ejecting ink from a nozzle onto recording paper. For example, in a method using a heat generating element as an energy generating element, the bottom wall of an ink liquid chamber (pressurizing chamber) communicating with a nozzle is configured by a heat generating element, and an electric pulse serving as an electric signal is applied to the heat generating element. Heating is performed, and ink is ejected from the nozzles by the pressure of the ink bubbles generated thereby, and recording is performed on the recording paper. Such non-impact recording type heads are excellent in high speed, low noise, etc., and are generally widely used.

  Here, in a general head structure, a nozzle sheet in which a plurality of nozzles for ejecting ink is formed is disposed on one side surface, and an ink flow path is disposed on the other side surface. A supply port or a buffer tank for supplying ink to the pressure chamber is provided. In addition, a wiring board for applying an electric pulse for ejecting ink to the heating element is connected. This wiring board connection method includes NCF (Non Conductive Film), NCP (Non Conductive Paste), ACP (Anisotropic Conductive Film), ACF (Anisotropic Conductive Film), and TAB (Tape Technology). Conventionally, the TAB method has been common, but an ACF method using an anisotropic conductive film has also been commercialized.

In addition, it is necessary to prevent corrosion due to ink and disconnection due to external force at the connection portion that electrically connects the wiring substrate, the exposed portion of the wiring substrate, and the like so as not to cause ejection defects. Therefore, it is sealed with a sealing material such as an epoxy-based, silicon-based or acrylic adhesive.
For example, in Patent Document 1, in a structure in which a head chip composed of a circuit board and a piezoelectric ceramic plate is connected via a flexible wiring board via an ACF, the outer periphery of the connecting portion is extended over the entire range so that the connecting portion is blocked from outside air. A head sealed with two layers of adhesive is disclosed.
JP 2004-1382 A

Further, in Patent Document 2, a filler reservoir portion that communicates with a sealing region around the recording element substrate is provided, a thermosetting filler is injected into the filler reservoir portion, and the filler is caused to flow by heating. A method of manufacturing a head that fills a sealing region and controls the filler to an appropriate amount is disclosed.
Japanese Patent No. 3592172

  However, the above-mentioned Patent Document 1 cannot meet the demand for high-speed and high-precision recording. That is, with the recent progress in recording technology, high-speed and high-precision recording is required, and as a result, the nozzle, the pressurizing chamber, and the ink flow path communicating with the pressurizing chamber Increasingly finer. Then, when heat is applied to the head due to the influence of the manufacturing process and environmental operation, the viscosity of the adhesive in the connection part between the head chip and the flexible wiring board and the sealing part of the flexible wiring board temporarily decreases, and the adhesive A part of the components flow out due to separation or the like, and block the ink flow path communicating with the very fine pressurizing chamber, thereby causing ejection failure.

  For example, the components in a thermosetting epoxy resin adhesive used as an adhesive mainly include a main agent and a curing agent. The main agent is a liquid, and the curing agent is a solid (powder) having a diameter of 10 μm or more. Yes. When the adhesive is heated for adhesion, the viscosity of the adhesive is temporarily reduced to cause component separation. At this time, the main agent can enter the gap having a height of about 10 μm by its own surface tension, but the curing agent cannot enter the gap. As a result, only the main agent flows out through the gap and eventually accumulates in a part of the ink flow path to block the flow path.

On the other hand, in the technique of the above-mentioned Patent Document 2, in order to control the filler to an appropriate amount, the filler reservoir portion that communicates with the sealing region is purposely formed, which has disadvantages in manufacturing cost and work efficiency. large.
Therefore, the problem to be solved by the present invention is to prevent the sealing material from flowing out at the connection part or the exposed part of the wiring board with a simple configuration, so that high-speed and high-precision recording can be performed stably. And reducing 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 which is a hole for arranging the head chip therein and has a plurality of head chip arrangement holes larger than the outer shape of the head chip. A head module that discharges liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the chamber, wherein the nozzle sheet includes: On one side of the module frame, the nozzle is positioned in the head chip arrangement hole and is arranged so as to cover a part of the area of the head chip arrangement hole with respect to each head chip arrangement hole. In addition, the head chip is formed in a size that covers a part of the region of the head chip arrangement hole, the head chip has a pair of grooves formed in the barrier layer, and the energy generating element and the nozzle of the head chip Are arranged in each head chip arrangement hole from the other side surface of the module frame so that each groove is arranged on the nozzle sheet at a position where the nozzle is not formed. The electrode of the head chip arranged in the head chip arrangement hole is formed by the nozzle sheet of the head chip arrangement hole. The wiring board is exposed from an uncovered area, and the wiring board is electrically connected to the electrode of the wiring board and the electrode of the head chip, and on the surface side of the module frame where the nozzle sheet is provided. The gap between the head chip and the module frame on the side where the wiring board is arranged is sealed with a sealing material, so as to cover the exposed electrode of the head chip. It is characterized by that.

In the above invention, the head chip has a pair of grooves formed in the barrier layer. 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 arranged on the nozzle sheet side, and the electrode of the wiring board and the electrode of the head chip are electrically connected.
Further, the gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with a sealing material. Then, the outflow of the sealing material is prevented by a pair of grooves formed in the barrier layer of the head chip.

  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, the gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with the sealing material. Then, the outflow of the sealing material is prevented by a pair of grooves formed in the barrier layer of the head chip. Therefore, the flow path of the ink is not blocked by the leaked sealing material, and high-speed and high-precision recording can be performed stably. In addition, since the sealing material can be prevented from flowing out with a simple configuration, 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. 5A is a plan view showing one module frame 11. The head module 10 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. 5A) is formed so as to surround a part of the outer edge portion of each head chip arrangement hole 11b.

FIG. 5 shows a process of attaching the nozzle sheet 25 to the module frame 11. As shown in FIG. 5, 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.
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 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 20 has an outer shape slightly larger than the head chip arrangement hole 11b.

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. 5, 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 hidden by the nozzle sheet 25 (see FIG. 4). 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. 6 is a plan view showing a state where 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. 6, the front side is the sticking surface side of the nozzle sheet 25, but for ease of understanding of the drawing, the head chip 20 attached from the opposite side is shown by a solid line (hatched portion). 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). ACF is a film-like adhesive mixed with conductive particles based on epoxy resin, etc., and heat (heated at a temperature of about 150 ° C. to 230 ° C. for about 5 seconds to 15 seconds), pressure, Thus, the electrode 23 of the head chip 20 and the wiring pattern of the flexible wiring board 3 are bonded to each other, and the two are electrically conducted through conductive particles.

  As described above, the flexible wiring board 3 is connected to the head chip 20 via the anisotropic conductive film 28 (ACF). At the same time, the module frame 11 is connected via an anisotropic conductive film 28 (ACF). Then, an exposed surface of the anisotropic conductive film 28 (ACF) is formed in the gap between the head chip 20 and the module frame 11 (opposite the flow path 27), and is immersed in ink after the buffer tank 12 described later is bonded. It becomes an area to be done. Therefore, in this state, the ACF whose durability to ink is not guaranteed may come into contact with the ink and short-circuit, causing troubles such as disconnection.

  The nozzle sheet 25 and the flexible wiring board 3 cover the gap between the head chip 20 and the module frame 11. And the proximity | contact part of the outer edge of the nozzle sheet 25 and the outer edge of the flexible wiring board 3 is not sealed. Therefore, in this state, when the buffer tank 12 is filled with ink, the ink leaks to the outside.

  Therefore, a sealing material 29 made of a thermosetting epoxy resin adhesive is provided in the gap between the head chip 20 and the module frame 11 (opposite the flow path 27) to expose the anisotropic conductive film 28 (ACF). Seal the surface. Further, the gap between the outer edges of the flexible wiring board 3 and the outer edge of the nozzle sheet 25 is sealed by providing the resin 30 from the nozzle sheet 25 side.

  Here, the sealing material 29 is obtained by curing a thermosetting epoxy resin adhesive at 150 ° C. for 90 seconds and then at 120 ° C. for 3 minutes. The components in the thermosetting epoxy resin adhesive mainly include a main agent and a curing agent. The main agent is a liquid, and the curing agent is a solid (powder) having a diameter of 10 μm or more. And when an adhesive agent is heated for adhesion | attachment, the viscosity of an adhesive agent will fall temporarily and will be in the state which is easy to raise | generate a component separation. In other words, before heating, it tries to stay in the part where it was applied due to the viscosity of the adhesive itself, but during heat curing, the viscosity of the adhesive temporarily decreases and flows out of the application area. It becomes easy.

  The thickness of the barrier layer 24 of the head chip 20 is 10 μm, and when the viscosity of the adhesive is lowered, the main agent enters a gap of about 10 μm between the nozzle sheet 25 and the head chip 20 by its own surface tension. , No curing agent enters. As a result, only the main agent flows out through this gap without curing, and accumulates in the flow path 27 as it is. The main agent accumulated in the flow path 27 has a viscosity higher than that of the ink. If the flow path 27 in a portion communicating with the ink liquid chamber 26 is blocked, ink ejection failure is caused.

  However, in this embodiment, the pair of grooves 24a formed in the barrier layer 24 of the head chip 20 plays a role of blocking the flow of the adhesive and prevents the flow path 27 from being blocked. FIG. 7 is an enlarged plan view showing a peripheral portion of one head chip 20 of the module frame 11. FIG. 8 is a plan view showing a process of sealing the gap between the head chip 20 and the module frame 11.

  As shown in FIG. 7, the head chip 20 is arranged in the head chip arrangement hole 11 b so that the heating resistor 22 faces the nozzle 25 a (see FIG. 4) of the nozzle sheet 25. The head chip 20 is bonded to the nozzle sheet 25 by the barrier layer 24. Here, a pair of groove portions 24 a are formed in the barrier layer 24, and each groove portion 24 a is located on both the left and right sides with respect to the arrangement of the heating resistors 22. Therefore, each groove part 24a will be arrange | positioned on the nozzle sheet | seat 25 of the position in which the nozzle 25a is not formed.

  Such a groove 24 a is formed simultaneously with the barrier layer 24. That is, a resist is laminated on the entire surface on which the heating resistor 22 is provided by applying a photosensitive resin that can be dissolved in a subsequent process on the substrate on which the heating resistor 22 is formed. As the resist, for example, a photosensitive cyclized rubber resist, an exposure curable dry film resist, or the like is used. Further, as a method for applying to the substrate, an optimum method may be selected from spin coating, bar coating, curtain coating, meniscus coating, spray coating, and the like.

  Next, an active energy ray in an optimum wavelength band for exposing the resist is irradiated by an exposure device through a mask on which a pattern of the barrier layer 24 and the groove 24a is drawn. For this exposure machine, a contact aligner or a mirror projection aligner in which the mask and the pattern to be formed are 1: 1 may be used, or the mask may be larger than the pattern in which the mask is actually formed and a plurality of the same patterns may be used. A stepper or the like that repeats exposure (step & repeat exposure) may be used. In addition, when improving the patterning characteristic of the exposed part etc., you may add the process of baking after exposure.

  After the resist is partially exposed by irradiation with active energy rays through a mask to form the pattern of the barrier layer 24 and the groove 24a, the resist is developed with a predetermined developer. That is, by performing development using a method suitable for the resist from among paddle development, dip development, spray development, etc., the exposed portion is removed so that only the unexposed portion remains. Further, after the development, it is possible to rinse with a predetermined rinsing solution or water (pure water or ion-exchanged water) for the purpose of replacing the residual developer or cleaning the surface as necessary. Further, after that, heating for volatilizing moisture and solvent remaining on the surface, swing-off drying using a spinner, vacuum drying using a vacuum chamber, and natural standing in the atmosphere or nitrogen atmosphere may be performed.

  As described above, the groove 24a is formed at the same time as the barrier layer 24 by laminating a resist on the entire surface on which the heating resistor 22 is provided and then removing unnecessary portions by a photolithography process. Therefore, the barrier layer 24 and the groove 24a can be easily formed in the same process, and the burden on the cost and work efficiency is small.

  As described above, the head chip 20 is arranged in the head chip arrangement hole 11 b and bonded to the nozzle sheet 25 by the barrier layer 24. Then, the gap between the head chip 20 and the module frame 11 is a portion on the nozzle sheet 25 that becomes the flow path 27 and an exposed surface portion of the anisotropic conductive film 28 (see FIG. 4) in the flexible wiring board 3. Although the exposed surface portion of the anisotropic conductive film and the adjacent portion between the outer edge of the nozzle sheet 25 and the outer edge of the flexible wiring substrate 3 are divided by a sealing material 29 made of a thermosetting epoxy resin adhesive, Sealed in a mold.

  Here, when the thermosetting epoxy resin adhesive is heated for sealing, the viscosity temporarily decreases, and the adhesive tends to flow to the flow path 27 on the nozzle sheet 25. That is, the thermosetting epoxy resin adhesive and the separation component (main agent) of the adhesive enter a gap of about 10 μm between the nozzle sheet 25 and the head chip 20 due to surface tension. However, in this embodiment, as shown in FIG. 8, the groove portion 24 a plays a role of storing the adhesive, and prevents the groove portion 24 a from flowing out onto the nozzle sheet 25. Therefore, as shown in FIG. 7, the U-shaped sealing material 29 up to the groove 24a is formed, and the flow path 27 is not blocked.

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 an adhesive to the module frame 11, the adhesive is heated and cured with the buffer tank 12 positioned and fixed. In the present embodiment, the same thermosetting epoxy resin adhesive as that of the sealing material 29 is used as the adhesive for the buffer tank 12, but other adhesives may be used.

In this embodiment, the buffer tank 12 is also a rigid support member for fixing the module frame 11. When the buffer tank 12 is mounted on the module frame 11, it covers all the head chip arrangement holes 11 b. It becomes like this. As shown in FIG. 4, the buffer tank 12 and the ink liquid chamber 26 of each head chip 20 are communicated 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.

  Further, as shown in FIG. 2, the buffer tanks 12 of the eight head modules 10 are visible. The buffer tanks 12 connected in series are connected by a U-shaped tube 13. Further, the connection side end portions (hatched portions in FIG. 2) of the two flexible wiring boards 3 extend perpendicular to the paper surface with respect to one head module 10.

  Next, as shown in FIG. 3, the control substrate 4 for controlling the discharge of the liquid and the like is screwed by screws 5 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 wiring board 3 passes through the notch 4b and goes out from the lower side to the upper side of the control board 4, and the control board 4 connector 4a.

  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.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications such as the following can be made. That is,
In the present embodiment, the groove 24a has a quadrangular shape, but the present invention is not limited to this, and may be a triangular or semicircular groove. Also, anything can be used as long as it can prevent the adhesive from flowing out as a sealing material that seals the gap between the head chip 20 on the side where the flexible wiring board 3 is disposed and the module frame 11. A pair of protrusions may be formed on the barrier layer 24 instead of the groove.

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 control board to 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 the process of sticking a nozzle sheet | seat on a module frame. 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 expands and shows the peripheral part of one head chip of a module frame. It is a top view which shows the process of sealing the clearance gap between a head chip and a 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 | positioning hole 20 Head chip 21 Semiconductor substrate 22 Heating resistor (energy generating element)
23 Electrode 24 Barrier Layer 24a Groove 25 Nozzle Sheet 25a Nozzle 26 Ink Liquid Chamber 29 Sealing Material

Claims (7)

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 arranging the head chips therein and are larger than the outer shape of the head chip are formed,
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 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 has a pair of grooves formed in the barrier layer, the energy generating element of the head chip and the nozzle are opposed to each other, and each of the grooves is at a position where the nozzle is not formed. From the other side surface of the module frame so as to be arranged on the sheet, each head chip is arranged in each hole,
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. Arranged to cover the electrode,
A gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with a sealing material. The head module according to claim 1,
The wiring module and the head chip are connected to each other through an anisotropic conductive film. 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 arranging the head chips therein and are larger than the outer shape of the head chip are formed,
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 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 has a pair of protrusions formed on the barrier layer, the energy generating element of the head chip and the nozzle face each other, and the protrusions are located at positions where the nozzle is not formed. From the surface on the other side of the module frame to be disposed on the nozzle sheet, each head chip is disposed in each hole,
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. Arranged to cover the electrode,
A gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with a sealing material. 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 arranging the head chips therein and are larger than the outer shape of the head chip are formed,
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 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 has a pair of grooves formed in the barrier layer, the energy generating element of the head chip and the nozzle are opposed to each other, and each of the grooves is at a position where the nozzle is not formed. From the other side of the module frame to be placed on the seat, each head chip placement hole is placed,
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. Arranged to cover the electrode,
The liquid ejection head, wherein a gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with a sealing material. 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 arranging the head chips therein and are larger than the outer shape of the head chip are formed,
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 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 has a pair of grooves formed in the barrier layer, the energy generating element of the head chip and the nozzle are opposed to each other, and each of the grooves is at a position where the nozzle is not formed. From the other side of the module frame to be placed on the seat, each head chip placement hole is placed,
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. Arranged to cover the electrode,
The liquid ejection device, wherein a gap between the head chip on the side where the wiring board is disposed and the module frame is sealed with a sealing material. 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,
A pre-process for forming a pair of grooves in the barrier layer of the head chip;
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;
The energy generating element of the head chip and the nozzle face each other under a second temperature environment lower than the first temperature environment, and each groove portion is on the nozzle sheet at a position where the nozzle is not formed. A second step of adhering the head chip to each of the head chip arrangement holes from the other surface of the module frame so as to be arranged;
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 sealing a gap between the head chip on the side where the wiring board is disposed and the module frame with a sealing material. In the manufacturing method of the head module according to claim 6,
The pre-process is characterized in that the groove is formed simultaneously with the barrier layer by laminating a resist over the entire surface on which the energy generating element is provided, and then removing unnecessary portions by a photolithography process. Manufacturing method of the head module.

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