JP4630592B2 - Manufacturing method of inkjet head unit - Google Patents

Description

The present invention relates to a manufacturing method of the ink jet head unit comprising an ink jet head for discharging ink as ink droplets.

  As an inkjet head, the inkjet head mounted in an inkjet printer etc. is mentioned, for example. The ink jet head basically includes an ink ejection substrate that forms a pressure chamber for ejecting ink, a nozzle that communicates with the pressure chamber, and the like, and ejects ink in the pressure chamber as ink droplets from the nozzle.

  Such an ink jet head is unitized by being bonded to a base substrate together with a drive circuit substrate having a drive circuit for driving and controlling it. Usually, an ink discharge substrate of an inkjet head is directly bonded to the base substrate with an adhesive. As the adhesive, a thermosetting epoxy adhesive or the like is used. This epoxy adhesive has high strength and has high reliability because it hardly causes permeation swelling / deterioration with respect to the cleaning agent used in the ink or inkjet head manufacturing process. However, since the curing temperature exceeds 100 ° C., the difference from the practical temperature of 20 to 30 ° C. is large, which causes warping.

  On the other hand, Patent Document 1 proposes a technique for reducing the occurrence of warpage by providing a substrate having a thermal expansion coefficient close to that of the ink discharge substrate between the ink discharge substrate and the base substrate. Patent Document 2 proposes a technique for reducing the occurrence of warping by increasing the strength of the ink discharge substrate or decreasing the strength of the base substrate.

JP 2000-351215 A JP 2002-337343 A

  However, in Patent Document 1 and Patent Document 2, a substrate having a thermal expansion coefficient close to that of the ink discharge substrate or a substrate for increasing the strength of the ink discharge substrate is required, and these substrates necessarily have high thermal conductivity. Therefore, the effect of suppressing temperature rise and temperature unevenness due to heat generation of the ink discharge substrate is reduced.

  In Patent Document 1, amorphous carbon or aluminum nitride is used as a material for a substrate having a thermal expansion coefficient close to that of an ink ejection substrate, based on the thermal expansion coefficient. The thermal conductivity of the substrate material described in Patent Document 1 is 200 W / mK for aluminum, 100 W / mK for silicon, 150 W / mK for aluminum nitride, 5 W / mK for amorphous carbon, and 40 W / mK for alumina. For this reason, when amorphous carbon is used as a substrate material as in Patent Document 1, the effect of suppressing temperature rise and temperature unevenness due to heat generation of the ink discharge substrate is reduced. In addition, when aluminum nitride is used as the base material, the effect of suppressing temperature rise and temperature unevenness due to heat generation of the ink discharge substrate is not reduced, but the cost of the inkjet head increases because aluminum nitride is expensive. Resulting in.

  Furthermore, Patent Document 1 and Patent Document 2 require a substrate having a thermal expansion coefficient close to that of the ink discharge substrate or a substrate for increasing the strength of the ink discharge substrate, which increases the number of components and increases the cost of the inkjet head. End up. In addition, since the required substrate, the ink discharge substrate, and the base substrate are bonded with an adhesive, there are two adhesive layers between them, compared to the case of only one adhesive layer, Warpage generated by expansion or contraction of the adhesive layer is increased.

The object of the present invention is to reduce the warpage that occurs when the ink ejection substrate is attached to the base substrate, and further to improve the ink ejection stability and reduce the density unevenness by diffusing the heat generated on the ink ejection substrate. An inexpensive inkjet head unit manufacturing method is provided.

The present invention provides an inkjet head unit by laminating a base substrate and an ink ejection substrate that forms a pressure chamber for ejecting ink by bonding the contact surfaces that contact each other when they are stacked. In the manufacturing method of the ink jet head unit to be manufactured, the central region in the longitudinal direction of the contact surface of the ink discharge substrate is applied to the contact surface of the base substrate with a high-strength adhesive having a stronger adhesive force than the permeable adhesive having permeability. Then, the penetrating adhesive is infiltrated between the ink discharge substrate and the base substrate with respect to both end regions of the contact surface of the ink discharge substrate, and the contact surface of the ink discharge substrate becomes the base substrate. It is characterized by adhering to the contact surface.

  According to the present invention, the warpage generated when the ink discharge substrate is attached to the base substrate is reduced, and further, the heat generation in the ink discharge substrate is diffused, thereby improving the ink discharge stability and reducing the density unevenness. An inexpensive ink jet head unit can be provided.

The prerequisite technology of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view schematically showing an inkjet head unit 1 according to the premise technique .

  As shown in FIG. 1, an inkjet head unit 1 includes an inkjet head that ejects ink as ink droplets from a base substrate 2 that holds various members and the like, and nozzles 4 that are provided on the base substrate 2 and formed on a nozzle plate 3. 5. A drive circuit board 6 having a drive IC (not shown) which is provided on the same side of the base substrate 2 as the inkjet head 5 and is a drive circuit for driving the inkjet head 5, the inkjet head 5 and the drive circuit board And the wiring portion 7 and the like that are electrically connected to each other.

  The inkjet head 5 includes a nozzle plate 3 in which a plurality of nozzles 4 are formed, an ink ejection substrate 8 that forms a plurality of pressure chambers (not shown) for ejecting ink, and a common ink chamber that communicates with these pressure chambers. And an ink chamber substrate 9 (not shown). The plurality of pressure chambers are provided at positions facing the plurality of nozzles 4, respectively, and are configured to be supplied with ink from a common ink chamber. The ink discharge substrate 8 forms at least a part of the pressure chamber.

  The ink discharge substrate 8 is formed of a piezoelectric member or the like, and is electrically connected to the drive IC of the drive circuit substrate 6. The ink discharge substrate 8 is configured to discharge the ink in the pressure chamber as ink droplets from the nozzles 4 of the nozzle plate 3 by deforming the volume of the pressure chamber based on drive control by the drive IC. In addition, although a piezoelectric element (piezo element) etc. are used as a piezoelectric member, it is not restricted to this.

  The ink chamber substrate 9 is formed with an ink supply port 10 for supplying ink to the common ink chamber. An ink tank (not shown) that stores ink is connected to the ink supply port 10 via an ink supply path 11. Thus, the ink stored in the ink tank is supplied from the ink supply port 10 to the common ink chamber via the ink supply path 11.

  As the ink, various inks such as water-based ink, oil-based ink, solvent ink, and UV ink (ultraviolet curable ink) are used. The UV ink is composed of, for example, a pigment, a monomer, an oligomer, a photopolymerization initiator, a dispersant, and other additives (for example, a surface tension adjusting agent).

  Such an ink jet head 5 supplies the pressure chamber by applying pressure to the ink by changing the volume of the desired pressure chamber of the ink discharge substrate 8 based on the drive control of the drive circuit board 6 by the drive IC. The discharged ink is selectively ejected from a plurality of nozzles 4 as ink droplets. In the process of increasing the volume of the pressure chamber, the ink in the common ink chamber is sucked into the pressure chamber, and in the process of decreasing the volume of the pressure chamber, the ink in the pressure chamber is ejected as an ink droplet from the nozzle 4 to the outside. To do.

In the base technology , the piezoelectric inkjet head 5 using a piezoelectric member (for example, a piezo element) is used as a discharge force generating member. However, the invention is not limited to this. For example, a heating element is used as the discharge force generating member. A thermal-type ink-jet head using the above may be used. In either method, the ink in the pressure chamber is ejected as ink droplets from the nozzle 4 by applying pressure to the ink in the pressure chamber (pressure due to volume change in the pressure chamber or pressure due to bubbles).

  Such an ink jet head 5 is bonded onto the base substrate 2 by two types of adhesives 12 and 13 having different characteristics. That is, the ink discharge substrate 8 and the base substrate 2 of the inkjet head 5 are formed by adhering and laminating the contact surfaces 8a and 2a that contact each other when they are laminated.

  As the two types of adhesives 12 and 13 having different characteristics, a high-strength adhesive 12 and an elastic adhesive 13 are used. For example, a member having high thermal conductivity is used as the base substrate 2.

  The high-strength adhesive 12 is an adhesive having a stronger adhesive force (high strength) than the elastic adhesive 13. The high-strength adhesive 12 is also an environmental resistant adhesive having excellent environmental resistance characteristics that do not lower its adhesive strength with respect to ink, cleaning agents, and the like. For example, an epoxy adhesive is used as the high-strength adhesive 12. As this epoxy adhesive, for example, a one-component thermosetting epoxy adhesive or the like is used.

On the other hand, the elastic adhesive 13 is an adhesive having elasticity even after curing. As the elastic adhesive 13, for example, an epoxy-based elastic adhesive is used. As the epoxy-based elastic adhesive, for example, a rubber-based / two-component mixed epoxy adhesive that is easily deformed is used. In the base technology , the high-strength adhesive 12 and the elastic adhesive 13 are thermosetting adhesives that are cured by heat.

  The ink discharge substrate 8 and the base substrate 2 of the ink jet head 5 are coated with a high-strength adhesive 12 at the central portion of the contact surface 2a of the base substrate 2, and with an elastic adhesive 13 at both ends thereof. The inkjet head 5 is laminated on the adhesives 12 and 13 and the adhesives 12 and 13 are cured to be bonded. Here, FIG. 2 is a plan view schematically showing the contact surface 8 a of the ink discharge substrate 8.

  In this way, the central region 14 (see FIG. 2), which is the first region of the contact surface 8a of the ink discharge substrate 8, is bonded to the contact surface 2a of the base substrate 2 with the high-strength adhesive 12. Further, both end regions 15 (see FIG. 2), which are the second regions of the contact surface 8 a of the ink discharge substrate 8, are bonded to the contact surface 2 a of the base substrate 2 by the elastic adhesive 13.

In the base technology , the central region 14 is the middle of three regions obtained by dividing the contact surface 8a of the ink discharge substrate 8 by two parallel lines perpendicular to the direction in which the pressure chambers are arranged (that is, the direction in which the nozzles 4 are arranged). The two end regions 15 are regions at both ends of the three regions, but are not limited thereto. Further, the area of the central region 14 is considerably smaller than the area of the both end regions 15. Thereby, the influence on the curvature etc. by expansion | swelling or shrinkage | contraction of the high intensity | strength adhesive agent 12 apply | coated to the center area | region 14 can be reduced.

  Next, the manufacturing method of the inkjet head unit 1 provided with the adhesion process which adhere | attaches the inkjet head 5 and the base substrate 2 is demonstrated with reference to FIG.1 and FIG.2.

  The inkjet head unit 1 is manufactured by bonding the central region 14 of the contact surface 8 a of the ink discharge substrate 8 of the inkjet head 5 to the contact surface 2 a of the base substrate 2 with the high-strength adhesive 12 and simultaneously using the elastic adhesive 13. An adhesion step of adhering both end regions 15 of the contact surface 8 a of the ink discharge substrate 8 of the inkjet head 5 to the contact surface 2 a of the base substrate 2 is provided.

  In this bonding step, first, the high-strength adhesive 12 is applied to the central portion of the contact surface 2a of the base substrate 2, and the elastic adhesive 13 is applied to both end portions (application step). Next, the inkjet head 5 is laminated on the two types of adhesives 12 and 13 applied on the contact surface 2a of the base substrate 2, and the adhesives 12 and 13 are thermally cured simultaneously (thermosetting step). Here, for example, the base substrate 2 on which the inkjet head 5 is laminated via the two types of adhesives 12 and 13 is placed in an oven or the like and heated to cure the two types of adhesives 12 and 13 simultaneously.

  In this way, the central region 14 (see FIG. 2) of the contact surface 8a of the ink discharge substrate 8 is bonded to the contact surface 2a of the base substrate 2 by the high-strength adhesive 12, and both ends of the contact surface 8a of the ink discharge substrate 8 are bonded. The region 15 (see FIG. 2) is bonded to the contact surface 2 a of the base substrate 2 by the elastic adhesive 13. Thereby, the inkjet head 5 is bonded and fixed on the base substrate 2, and the inkjet head unit 1 is completed.

As described above, according to the base technology , necessary strength (adhesive force) is given to the ink discharge substrate 8 and the base substrate 2 by the adhesive force of the high-strength adhesive 12, and the ink discharge substrate by the elasticity of the elastic adhesive 13. 8 and the warp due to expansion and contraction of the base substrate 2 can be suppressed. As a result, it is possible to reduce warpage that occurs when the ink discharge substrate 8 is attached to the base substrate 2. Further, since the ink discharge substrate 8 is directly provided on the base substrate 2 having high thermal conductivity, it is possible to improve the ink discharge stability and reduce the density unevenness by diffusing the heat generated in the ink discharge substrate 8. it can. Moreover, the inexpensive inkjet head unit 1 can be provided without increasing the number of parts as in the prior art.

  Further, only the central region 14 of the contact surface 8a of the ink discharge substrate 8 is adhered to the contact surface 2a of the base substrate 2 with the high-strength adhesive 12, thereby making the ink discharge substrate 8 and the base substrate 2 high over the entire surface. Compared with the case of bonding with the strength adhesive 12 alone, it is possible to reduce the warp caused by the expansion and contraction of the high strength adhesive 12. Further, both the moments applied to both end portions of the ink discharge substrate 8 are both compared to the case where the area other than the central region 14 of the contact surface 8a of the ink discharge substrate 8 is bonded to the contact surface 2a of the base substrate 2 with the high strength adhesive 12. Since both can be reduced, the warpage of the ink discharge substrate 8 can be reduced.

An embodiment of the present invention will be described with reference to FIGS. FIG. 3 is an exploded perspective view schematically showing the inkjet head unit 1 of the present embodiment, and FIG. 4 is an external perspective view schematically showing the inkjet head unit 1 of the present embodiment.

The present embodiment is basically the same as the above-described base technology, and the difference between them will be described here. In addition, the part demonstrated by the base technology is shown with the same code | symbol, and the description is also abbreviate | omitted.

  As shown in FIGS. 3 and 4, the inkjet head 5 is bonded onto the base substrate 2 with two types of adhesives 21 and 22 having different characteristics. That is, the ink discharge substrate 8 and the base substrate 2 of the inkjet head 5 are formed by adhering and laminating the contact surfaces 8a and 2a that contact each other when they are laminated.

  As two types of adhesives 21 and 22 having different characteristics, a high-strength adhesive 21 and a penetrating adhesive 22 are used. For example, a member having high thermal conductivity is used as the base substrate 2.

  The high-strength adhesive 21 is an adhesive having a stronger adhesive force (high strength) than the penetrating adhesive 22. Further, the high-strength adhesive 21 is also an environment-resistant adhesive having excellent environmental resistance characteristics in which the adhesive strength does not decrease with respect to ink, cleaning agents, and the like. For example, an epoxy adhesive is used as the high-strength adhesive 21. As this epoxy adhesive, for example, a one-component thermosetting epoxy adhesive or the like is used. In the present embodiment, the high-strength adhesive 21 is a thermosetting adhesive that is cured by heat.

  On the other hand, the penetrating adhesive 22 is an adhesive having penetrability (fluidity). As the osmotic adhesive 22, for example, an anaerobic adhesive that hardens when cut off from air is used. As this anaerobic adhesive, an instantaneous adhesive or the like is used. The penetrating adhesive 22 may be an adhesive having photocuring characteristics in addition to anaerobic characteristics.

  The ink discharge substrate 8 and the base substrate 2 of the inkjet head 5 are formed by applying a high-strength adhesive 21 to the central portion of the contact surface 2 a of the base substrate 2 and laminating the inkjet head 5 on the high-strength adhesive 21. The high-strength adhesive 21 is cured, and the penetrating adhesive 22 is injected between the ink discharge substrate 8 and the base substrate 2 to be cured.

  In this way, the central region 14 (see FIG. 2), which is the first region of the contact surface 8a of the ink ejection substrate 8, is bonded to the contact surface 2a of the base substrate 2 by the high-strength adhesive 21. Further, both end regions 15 (see FIG. 2) that are the second regions of the contact surface 8 a of the ink ejection substrate 8 are bonded to the contact surface 2 a of the base substrate 2 by the penetrating adhesive 22.

In the present embodiment, the central region 14 is the middle of three regions obtained by dividing the contact surface 8a of the ink ejection substrate 8 by two parallel lines perpendicular to the direction in which the pressure chambers are arranged (that is, the direction in which the nozzles 4 are arranged). a region (longitudinal direction of the central area of the contact surface 8a of the ink discharge substrate 8), the ends regions 15, Ru region der of both ends of the three regions. Further, the area of the central region 14 is considerably smaller than the area of the both end regions 15. Thereby, the influence on the curvature etc. by expansion | swelling or shrinkage | contraction of the high intensity | strength adhesive agent 12 apply | coated to the center area | region 14 can be reduced.

  Next, the manufacturing method of the inkjet head unit 1 provided with the adhesion process which adhere | attaches the inkjet head 5 and the base substrate 2 is demonstrated with reference to FIG.3 and FIG.4.

  As shown in FIGS. 3 and 4, the method for manufacturing the inkjet head unit 1 uses the high-strength adhesive 21 to change the central region 14 of the contact surface 8 a of the ink discharge substrate 8 of the inkjet head 5 to the contact surface 2 a of the base substrate 2. Then, an adhesion process is provided in which both end regions 15 of the contact surface 8 a of the ink discharge substrate 8 of the inkjet head 5 are bonded to the contact surface 2 a of the base substrate 2 by the penetrating adhesive 22.

  In this bonding step, first, the high-strength adhesive 21 is applied to the central portion of the contact surface 2a of the base substrate 2 (application step: see FIG. 3). Next, the inkjet head 5 is laminated on the high-strength adhesive 21 applied on the contact surface 2a of the base substrate 2, and the high-strength adhesive 21 is thermally cured (thermosetting step). Here, for example, the high-strength adhesive 21 is cured by putting the base substrate 2 on which the inkjet head 5 is laminated via the high-strength adhesive 21 into an oven and heating it. Thereafter, a penetrating adhesive 22 is injected and applied between the contact surface 2a of the base substrate 2 and the contact surface 8a of the ink discharge substrate 8 (application process: see FIG. 4). Here, for example, the penetrating adhesive 22 is injected between the base substrate 2 and the ink discharge substrate 8 from both ends of the ink discharge substrate 8. At this time, the penetrating adhesive 22 penetrates between the base substrate 2 and the ink discharge substrate 8 and is cured immediately. When the penetrating adhesive 22 is an adhesive having photocuring characteristics in addition to anaerobic characteristics, the penetrating adhesive 22 protruding from both ends of the ink discharge substrate 8 is irradiated with light to penetrate the penetrating adhesive 22. 22 is cured (photocuring step: see FIG. 4).

  In this way, the central region 14 (see FIG. 2) of the contact surface 8a of the ink discharge substrate 8 is adhered to the contact surface 2a of the base substrate 2 by the high-strength adhesive 21, and both ends of the contact surface 8a of the ink discharge substrate 8 are adhered. The region 15 (see FIG. 2) is bonded to the contact surface 2 a of the base substrate 2 by the penetrating adhesive 22. Thereby, the inkjet head 5 is bonded and fixed on the base substrate 2, and the inkjet head unit 1 is completed.

  As described above, according to the present embodiment, a necessary strength (adhesive force) is given to the ink discharge substrate 8 and the base substrate 2 by the adhesive force of the high-strength adhesive 21, and the use of the penetrating adhesive 22 increases the strength. The heating time for the strength adhesive 21 is shortened, and the expansion and contraction of the ink discharge substrate 8 and the base substrate 2 are suppressed. Thereby, the curvature generate | occur | produced when attaching the ink discharge substrate 8 to the base substrate 2 can be reduced. Furthermore, since the ink discharge substrate 8 is directly provided on the base substrate 2 having high thermal conductivity, it is possible to improve the ink discharge stability and reduce the density unevenness by diffusing the heat generated on the ink discharge substrate 8. it can. Moreover, the inexpensive inkjet head unit 1 can be provided without increasing the number of parts as in the prior art.

  Further, only the central region 14 of the contact surface 8a of the ink discharge substrate 8 is adhered to the contact surface 2a of the base substrate 2 with the high strength adhesive 21 to thereby bond the ink discharge substrate 8 and the base substrate 2 to the high strength adhesive 21. Compared with the case where the adhesive is simply bonded, it is possible to reduce the warpage caused by the expansion and contraction caused by the high-strength adhesive 21. In addition, both the moments applied to both ends of the ink ejection substrate 8 are compared to the case where the high-strength adhesive 12 adheres the area other than the central region 14 of the contact surface 8a of the ink ejection substrate 8 to the contact surface 2a of the base substrate 2. Since it becomes possible to make it small, the curvature of the ink discharge substrate 8 can be reduced.

  When the penetrating adhesive 22 is injected between the base substrate 2 and the ink discharge substrate 8, the penetrating adhesive 22 may protrude and remain in the vicinity of the injection. When this amount of protrusion is large, it takes a considerable time until the portion is cured. Therefore, in addition to the anaerobic characteristics, the penetrating adhesive 22 has photocuring characteristics, and the penetrating adhesive 22 having the photocuring characteristics is cured by photocuring. As a result, the protruding penetrating adhesive 22 can be cured in a short time, and contamination to the surroundings by the uncured adhesive can be prevented.

1 is an exploded perspective view schematically showing an ink jet head unit of a prerequisite technology of the present invention. It is a top view which shows roughly the contact surface of the ink discharge board | substrate with which an inkjet head unit is provided. The implementation in the form of an ink jet head unit of the present invention is an exploded perspective view schematically showing. The implementation in the form of an ink jet head unit of the present invention is an external perspective view schematically showing.

DESCRIPTION OF SYMBOLS 1 Inkjet head unit 2 Base board | substrate 2a Contact surface 8 Ink discharge board | substrate 8a Contact surface 12 High strength adhesive 13 Elastic adhesive 14 1st area | region (central area | region)
15 Second region (both end regions)
21 High strength adhesive 22 Penetration adhesive

Claims (2)

An ink jet head for manufacturing an ink jet head unit by laminating a base substrate and an ink ejection substrate forming a pressure chamber for ejecting ink by bonding the contact surfaces that contact each other when they are laminated. In the unit manufacturing method,
The central region in the longitudinal direction of the contact surface of the ink discharge substrate is bonded to the contact surface of the base substrate with a high-strength adhesive having a stronger adhesive force than the penetrating adhesive having permeability, and then the ink discharge substrate The penetrating adhesive is infiltrated between the ink discharge substrate and the base substrate with respect to both end regions of the contact surface, and the contact surface of the ink discharge substrate is bonded to the contact surface of the base substrate.
A method for manufacturing an ink jet head unit. The penetrating adhesive is an adhesive having photocuring characteristics,
The penetrating adhesive was cured by irradiating the penetrating adhesive with light,
The manufacturing method of the inkjet head unit of Claim 2 characterized by the above-mentioned.

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