JP2006192584A - Inkjet head manufacturing method - Google Patents

Abstract

An inkjet head manufacturing method is provided that improves the protrusion of unnecessary adhesive into holes and grooves. A plurality of plates each having a through-hole or a groove are laminated via an adhesive layer. In the method of manufacturing an ink jet head in which a liquid flow path member having a liquid flow path formed therein is formed and a piezoelectric actuator is bonded to the surface of the liquid flow path member, the adhesive is applied to an adhesive transfer sheet made of an elastic body. After applying, bringing a dummy member into contact with the adhesive transfer sheet and transferring the adhesive applied to the surface of the adhesive transfer sheet to the dummy member, bringing the plate into contact with the adhesive transfer sheet The adhesive remaining on the surface of the adhesive transfer sheet is transferred to the plate. [Selection] FIG.

Description

  The present invention relates to an ink jet head manufacturing method, and more particularly to an ink jet head manufacturing method suitable for a print head using the vibration of a piezoelectric body.

  The print head, for example, pressurizes a liquid in a liquid pressure chamber provided in a flow path member, ejects liquid droplets from the liquid pressurization chamber, and records it on a recording medium. In such a channel member, a liquid channel is formed by laminating a plurality of plates each having a through hole or a groove via an adhesive layer.

  For example, in a conventional ink jet print head, a plurality of plates are stacked and the plates are bonded together with an adhesive to form an ink flow path such as an ink chamber, a pressure chamber, or a nozzle (for example, Patent Document 1). ).

  For example, FIG. 4 is a cross-sectional view schematically showing the configuration of a conventional ink jet print head. According to FIG. 4, the inkjet print head includes a piezoelectric plate formed by laminating a nozzle plate 121, a pool plate 122, a supply hole plate 123, a sealing plate 124, a pressure chamber plate 125, and a vibration plate 126. A pressure generator 127 such as an actuator or a heater is attached.

  A nozzle hole 128 for ejecting ink is formed in the nozzle plate 121, and the nozzle hole 128 is connected to the pool plate 121, the supply hole plate 123, and the nozzle communication hole 129 provided in the sealing plate 124. The pressure chamber 128 is connected to the pressure chamber 130 provided in the pressure chamber plate 125, and the pressure chamber 128 includes a supply communication path 131 formed in the sealing plate 124 and a supply hole 132 formed in the supply hole plate 123. To the ink pool 133 formed on the pool plate 121.

  Each plate was laminated and bonded via an adhesive, and an adhesive was used for lamination bonding. However, since each plate has holes and grooves with very small diameters such as nozzles and nozzle communication holes, the problem is that these holes are filled with adhesive, and the build-up 135a, 135b There was a problem that the flow was hindered and normal droplet ejection from the nozzle hole 128 was impossible.

Therefore, it has been proposed to apply an adhesive to an elastic plate, transfer a thin layer of adhesive applied on the plate to each plate, and press, bond, and fix a plurality of stacked plates ( For example, Patent Document 2).
JP-A-5-330067 Japanese Patent Laid-Open No. 3-97051

  However, although the adhesion method described in Patent Document 1 has the advantage that the protrusion of the adhesive into the flow path is reduced by providing the relief groove, the adhesive applied on the plate material is sufficiently thinned. It is difficult to transfer to the plate in excess of the required amount, and the adhesive protrudes at the time of bonding and blocks the ink flow path consisting of holes and grooves, resulting in variations in the ink discharge amount and discharge speed, or ink discharge. There was a problem that nozzles that do not occur.

  SUMMARY An advantage of some aspects of the invention is that it provides a method for manufacturing an ink-jet head that improves the protrusion of unnecessary adhesive into holes and grooves.

  The method of manufacturing an ink jet head according to the present invention includes laminating a plurality of plates each having a through hole or a groove via an adhesive layer to form a liquid flow path member having a liquid flow path formed therein, and the liquid. In a method of manufacturing an inkjet head in which a pressure generating device is bonded to the surface of a flow path member, the adhesive is applied to an adhesive transfer sheet made of an elastic body, a dummy member is brought into contact with the adhesive transfer sheet, and the adhesion is performed. After the adhesive applied to the surface of the adhesive transfer sheet is transferred to the dummy member, the plate is brought into contact with the adhesive transfer sheet, and the adhesive remaining on the surface of the adhesive transfer sheet is applied to the plate. It is characterized by transferring.

  In particular, the dummy member is preferably larger than the plate.

  Before transferring the adhesive applied to the adhesive transfer sheet to the plate, it is preferable to transfer the adhesive to the dummy member twice or less.

  In stacking the plurality of plates, it is preferable that an adhesive is applied to one of a pair of plate contact surfaces that contact each other, and an adhesive is not applied to the other plate contact surface.

  The adhesive layer thickness is preferably 0.3 to 2 μm or less.

  In the present invention, after removing the excess adhesive applied to the adhesive transfer sheet by bringing the dummy member into contact with the adhesive transfer sheet, the plate is brought into contact with the adhesive transfer sheet. Based on the new knowledge that unnecessary protrusion of the adhesive to the holes and grooves formed in each plate can be remarkably improved, as a result, it is possible to improve ink ejection variation and It is possible to prevent non-ejection of ink generated by clogging of the flow path.

  That is, when the adhesive is applied to the adhesive transfer sheet and the adhesive is directly transferred to the plate as in the conventional case, more adhesive than necessary is adhered on the plate, and excess adhesive is applied to the plate. Flowed into part or all of the holes and grooves. However, when the adhesive applied on the adhesive transfer sheet is once transferred to the dummy member as in the present invention, the excess adhesive is transferred to the dummy member and removed, and the adhesive The adhesive on the transfer sheet has a substantially uniform thickness. Therefore, by bringing the plate into contact with the adhesive transfer sheet, an appropriate amount of adhesive can be transferred to the plate, and filling of holes and grooves in the plate can be suppressed, and a very small amount of adhesive can be transferred to the holes and grooves. Even if the adhesive sticks to the edge portion and the adhesive protrudes, the flow of the liquid is not greatly hindered.

  Then, even when such plates are laminated and bonded, the adhesive does not flow into the holes and grooves, and an ink jet head can be provided in which the protrusion of unnecessary adhesive into the holes and grooves is improved.

  First, the structure of an inkjet head produced by the method for producing an inkjet head of the present invention will be described. An example in which a piezoelectric actuator is used as a pressure generating device constituting the ink jet head will be described.

  1A and 1B show the structure of an inkjet head according to the present invention. FIG. 1A is a schematic sectional view, FIG. 1B is a plan view seen from the nozzle hole side, and FIG. 1C is a plan view seen from the pressure generator side. Is.

  According to FIG. 1, it has a structure in which a vibration generating device 7 made of a piezoelectric actuator or the like is provided on a flow path member. For example, the vibration generating device 7 includes a common electrode, an active layer on a vibration plate. And the individual electrodes provided on the surface of the piezoelectric ceramic layer are sequentially formed. By providing a plurality of individual electrodes on the surface of the piezoelectric ceramic layer, a plurality of piezoelectric displacement elements formed by sandwiching the piezoelectric ceramic layer between the common electrode and the individual electrodes are arranged on the diaphragm. Then, by applying a voltage between the common electrode and the individual electrode, piezoelectric vibration can be generated in the piezoelectric ceramic layer immediately below the individual electrode.

  For example, as shown in FIG. 1, the liquid flow path member of the present invention includes a nozzle plate 1, a pool plate 2, a supply hole plate 3, a sealing plate 4, a pressure chamber plate 5, and a vibration plate 6. And a pressure generator 7 is attached to the vibration plate 6.

  A nozzle hole 8 for ejecting liquid is formed in the nozzle plate 1, and the nozzle hole 8 is connected to the pool plate 2, the supply hole plate 3, and the nozzle communication hole 9 provided in the sealing plate 4. The pressure chamber 10 is connected to the pressure chamber 10 provided in the pressure chamber plate 5, and the pressure chamber 10 includes a supply communication path 11 formed in the sealing plate 4 and a supply hole 12 formed in the supply hole plate 3. To the liquid pool 13 formed on the pool plate 2.

  A liquid flow path is formed from the liquid pool 13 to the nozzle hole 8 through the supply hole 12, the supply communication path 11, the pressure chamber 10, and the nozzle communication hole 9. A plurality of fluid passages having such a configuration are provided in the fluid passage member, and as shown in FIGS. 1B and 1C, a plurality of nozzle holes 8 are formed in the nozzle plate 1, A pressure generator corresponding to each nozzle hole 8 is provided on the vibration plate 6.

  Then, the vibration plate is vibrated by driving the piezoelectric actuator used as the pressure generating device, the volume of the pressure chamber 10 is changed, and a droplet can be ejected from the nozzle hole 8. Note that the pressure generators 7 are controlled independently of each other so that the liquid droplets are ejected every nozzle hole 8.

  It should be noted that the structure of the flow path member such as the combination of each plate and the layer structure is not limited to that shown in FIG. 1, and the present invention can be applied to any combination. Moreover, although the piezoelectric actuator is formed on the vibration plate, it may be joined so that the surface of the actuator forms the wall surface of the pressure chamber 10.

  As the structure of the piezoelectric actuator, any structure can be used as long as the volume of the pressure chamber can be changed and a droplet can be ejected from the nozzle hole 8. Also, a pressure generating device other than the piezoelectric actuator can be used. For example, an electrostatic system or a heating system can be exemplified.

  For the plates 1 to 6 constituting the flow path member, a desired material such as metal, ceramics, or resin can be used, but it is preferable to use metal in terms of workability. In particular, the plate material is preferably formed of at least one selected from the group consisting of Fe—Cr, Fe—Ni, and WC—TiC. Thereby, the flow path excellent in ink resistance can be formed.

  Each of the metal plates 1 to 6 is obtained by a rolling method or the like, and through holes or grooves can be formed as desired. For the processing of the holes and grooves, a known method such as punching with a mold or etching can be employed.

  The plates 1 to 6 are laminated and bonded via an adhesive layer, and a liquid flow path is formed inside the flow path member by a combination of through holes and grooves provided in each of the plates 1 to 6. be able to.

  When pressure is generated from a pressure generating device such as a piezoelectric actuator, the liquid filled in the nozzle communication hole 9 in the vicinity of the nozzle hole 8 is ejected to the outside as a liquid droplet. Is supplied from the pressure chamber 10 to the nozzle communication hole 9, and the pressure chamber 10 is supplied to the nozzle communication hole 9 from the supply communication path 11 to supply the shortage to the supply communication path 11. Is supplied from the liquid pool 13 through the supply hole 12.

  At that time, it is important to reduce the amount of the adhesive protruding so as not to disturb the liquid flow. For example, as shown in FIG. 2 or 3, since the build-up 5a, 5b is made small and the liquid flow is not hindered, a predetermined amount of droplets can be ejected from the nozzle hole 128 at a predetermined speed. FIG. 2 is an enlarged view of a part of FIG. 1 when the viscosity of the adhesive is relatively increased, and FIG. 3 is an enlarged view of a part of FIG. 1 when the viscosity of the adhesive is relatively decreased. Also, the same numbers are assigned to the common parts with FIG.

  Next, the manufacturing method of the inkjet head of this invention is demonstrated.

  First, plates 1 to 6 and piezoelectric actuators having desired through holes and grooves are prepared. These plates 1 to 6 have a thickness of 0.03 to 0.3 mm, and the plates 1 to 6 can have a desired thickness according to the structure and the site.

  Then, these plates 1 to 6 are bonded. The adhesive is at least one thermosetting resin selected from the group consisting of epoxy resin, phenol resin, and polyphenylene ether resin having a thermosetting temperature of 80 to 200 ° C. so as not to affect the piezoelectric actuator and the flow path member. It is preferable to use an adhesive of the type because the residual stress can be suppressed from being generated in the piezoelectric actuator and the piezoelectric characteristics of the piezoelectric actuator can be prevented from deteriorating.

  According to the present invention, the bonding is performed by (1) an application step of applying an adhesive to the adhesive transfer sheet, (2) an appropriate amounting step of transferring the adhesive applied to the adhesive transfer sheet to a dummy member, (3 ) It is important to have four steps: a transfer step for transferring the adhesive remaining on the adhesive transfer sheet to the plate, a plate for transferring the adhesive, and a bonding step for joining the other plate to be bonded to this plate. It is.

(Coating process)
In the application step, the adhesive is applied onto the adhesive transfer sheet by a known method such as a doctor blade method, a roll coater method, a die coater method, or a screen printing method. At this time, the adhesive does not necessarily have a uniform thickness and has irregularities, but it is preferable to make the irregularities as small as possible.

  In the coating process, the amount of the adhesive applied to the adhesive transfer sheet is slightly larger than the amount of the adhesive used for bonding between the plates, and can effectively suppress the occurrence of a portion where the adhesive is not applied. Therefore, it is preferable. Specifically, the thickness of the adhesive coating layer applied to the adhesive transfer sheet is 2 to 20 μm, particularly 2 to 15 μm, and more preferably 2 to 10 μm, for the reason of stabilizing the adhesive transfer amount, preferable.

  In addition, the adhesive can be applied by a single application, a plurality of times, a partial application, an overall application, or a combination thereof, and a desired part. What is necessary is just to be able to apply an adhesive.

(Weighing process)
Since the amount of the adhesive layer applied and formed on the surface of the adhesive transfer sheet in the application step is larger than the appropriate amount, it can be transferred to a dummy member to remove excess adhesive. In addition, by bringing the dummy member into contact with the adhesive application surface of the adhesive transfer sheet, the unevenness of the adhesive remaining on the surface of the adhesive transfer sheet can be reduced, and the thickness of the adhesive layer can be made uniform. Can do.

  It is preferable that the dummy member has an outer dimension larger than that of the plate to be actually bonded, because it is easy to align the plate within the transfer region to the dummy member. Specific examples of the material include alumina, Mo, 42 alloy (Fe-42Ni alloy), Cu, SUS316 steel, and vinyl chloride.

  The dummy member is preferably one having a smooth surface and a large main surface. Specifically, a flat plate such as a plate or a base plate shape is preferable.

  It is preferable that the process of optimizing the surplus adhesive by bringing the adhesive applied to the adhesive transfer sheet into contact with the dummy member is not more than twice. This ensures a necessary and sufficient transfer amount of adhesive to the plate, can easily prevent unnecessary communication between the flow paths due to insufficient adhesive, and easily stabilize the ink discharge amount and discharge speed. It is also easy to make it.

  When a dummy member is brought into contact with the adhesive transfer sheet, approximately 30 to 70% of the adhesive coating layer formed on the surface of the adhesive transfer sheet is transferred to the dummy member, depending on the material and surface state of both. Therefore, if the removal amount is measured in advance, the thickness of the remaining adhesive can be adjusted.

  Moreover, it is preferable to make it the method of pulling away in the direction perpendicular | vertical to an adhesive surface, when separating the adhesive transfer sheet and dummy member which contacted in the appropriate quantity formation process.

(Transfer process)
A desired plate is brought into contact with the adhesive application surface of the adhesive transfer sheet from which excess adhesive has been removed in an appropriate amount process, and a part of the adhesive on the surface of the adhesive transfer sheet is transferred to the surface of the plate. Since 30 to 70% of the adhesive of the adhesive layer formed on the surface of the adhesive transfer sheet is transferred, the amount of transfer to the plate can be controlled by controlling the thickness of the adhesive layer that has undergone an appropriate amount process. Can be controlled.

  The size of the plate should be smaller than the size of the adhesive transfer sheet, so that the entire surface can be transferred at one time, which is preferable for controlling the transfer amount.

(Adhesion process)
In the transfer process, the plate to which the adhesive has been transferred is bonded to another plate. For adhesion, pressurization for joining can be performed. The pressure applied is preferably 0.05 to 1 MPa, particularly 0.1 to 0.5 MPa for controlling the thickness of the adhesive layer.

  Since the curing of the adhesive takes place as the crosslinking reaction proceeds, it is preferable to treat the adhesive so that the curing is completed in a state of being heated and pressurized. Needless to say, in bonding, the positions are aligned with each other.

  The bonded body bonded in this way can prevent the adhesive from protruding into the internal liquid passage, and as a result, can effectively prevent the blockage of the flow path. That is, according to the present invention, by transferring the adhesive to the dummy member, the adhesive is not transferred to the plate more than necessary, and the adhesive protrudes into the through hole or groove portion of the plate. In addition, since it is possible to prevent the portion that becomes the ink flow path from being blocked, it is possible to improve the problem that the ink discharge amount and the discharge speed vary, or nozzles that do not discharge ink are generated.

  After making a laminate by bonding a pair of plates, a plate to which another adhesive has been transferred may be further adhered to the laminate, or a plurality of plates may be laminated at one time. It may be cured and bonded. In addition, the manufacturing method of the present invention may be applied to bonding between all plates, or may be applied to partial bonding.

  Adhesive on the adhesive surface can be bonded if it is on at least one surface, but only one of them can be taken into consideration when controlling the thickness of the adhesive and intrusion of the amount of adhesive into the through-hole or groove provided in the plate It is better to transfer the adhesive to the surface.

  The dummy member is preferably larger than the plate that becomes the flow path member. In order to ensure that the plate to which the adhesive is transferred next is brought into contact with the area where the adhesive has been transferred to the dummy member, the dummy member should be 10 mm or more, preferably 20 mm or more larger than the plate. good.

  The surface of the dummy member is preferably a flat surface. Excluding the through holes, deep grooves or large protrusions is preferable in terms of precisely controlling the amount of adhesive.

  In stacking the plates, it is preferable to apply an adhesive to one of a pair of plate contact surfaces that contact each other and not apply an adhesive to the other plate contact surface. By applying the adhesive only to one of the contact surfaces, the amount of the adhesive can be prevented from being increased more than necessary, and the protrusion of the adhesive into the flow path can be easily controlled.

  The thickness of the adhesive layer is preferably 0.3 to 2 μm, particularly preferably 0.3 to 1.5 μm, and more preferably 0.5 to 1.5 μm. As a result, it becomes easy to secure a necessary and sufficient adhesive material, it becomes easy to suppress the occurrence of unnecessary communication between the flow paths due to poor adhesion, and excess adhesive protrudes into the flow paths. It becomes easy to suppress, and as a result, the ink discharge amount and the discharge speed are stabilized.

  As mentioned above, although embodiment of this invention was shown, it cannot be overemphasized that this invention can be applied not only to embodiment mentioned above but what was changed and improved in the range which does not deviate from the main point of this invention.

  Further, the present invention can be applied to an apparatus having a mechanism for delivering a liquid, such as a liquid discharge apparatus or a micropump.

  The liquid channel member shown in FIG. 1 was manufactured by repeatedly performing the above-described application step, appropriate amount step, transfer step, and adhesion step.

  In the coating process, the adhesive was applied to the surface of the adhesive transfer sheet with a squeegee. Table 1 shows the thickness of the adhesive coating layer formed on the surface of the adhesive transfer sheet when applied.

  In the appropriate quantity adjustment process, a dummy plate was prepared as a dummy member, and was brought into contact with the adhesive transfer sheet to remove excess adhesive. Table 1 shows the number of times of transfer to the dummy member. In addition, as an adhesive agent, an epoxy resin, a phenol resin, or a polyphenylene ether resin was used.

  In the transfer process, a stainless steel plate constituting the flow path was brought into contact with the adhesive transfer sheet from which excess adhesive was removed, and the adhesive remaining on the adhesive transfer sheet was transferred to the plate.

  This series of steps is repeated for each plate constituting each flow path, and the positions of these plates are aligned and laminated to form a laminated body. Thereafter, the laminated body of a plurality of plates is subjected to the pressure shown in Table 1. The adhesive was cured by heating at 150 ° C. for 30 minutes while applying pressure. In addition, the transfer of the adhesive was performed by transferring the adhesive only to one plate on the adhesive surface, and superposing it on the adhesive surface of the other plate without transferring the adhesive.

  The obtained liquid flow path member was aligned so that the piezoelectric element of the piezoelectric actuator was at the same position as the pressure chamber, and the piezoelectric actuator was joined to the liquid flow path member. The bonding was performed by heating at 150 ° C. for 30 minutes while applying pressure to cure the adhesive (epoxy adhesive). The thickness of the adhesive is shown in Table 1.

  In order to confirm whether or not the adhesive between the plates was insufficient and a space communicating between the plurality of pressure chambers was formed between the plates, a leak test was performed. In the leak test, a pressure of 60 kPa was kept applied for 70 seconds in the flow path, and whether or not the pressure was maintained and whether or not the pressure decreased were determined to determine the presence or absence of a leak. When there was a pressure drop of 2 kPa or more, it was judged that there was a leak.

  Next, in order to investigate whether or not the liquid droplets are normally ejected, an ink ejection test was performed on 30 nozzle holes out of 100 nozzle holes. That is, the ejection speed of the ink droplet was measured by continuously shooting the flying state of the ink droplet with a strobe. The ejection speed was calculated from the light emission interval of the strobe and the movement distance of the ink droplets. And, from the difference between the maximum value and the minimum value of the discharge speed, the range is 1.5 m / sec or less 、, 1.5 m / sec is exceeded and 2.5 m / sec or less is ○, 2.5 m / sec is exceeded Was displayed as x.

The results are shown in Table 1.

  Sample No. of the present invention. Nos. 4 to 15 had no blocked nozzle holes in the discharge test, and the difference between the maximum value and the minimum value of the discharge speed, that is, the variation was 2.3 m / sec or less and 21% or less of the maximum value.

  On the other hand, the sample No. which is not transferred to the dummy member is out of the scope of the present invention. In No. 1, a leak was observed in the leak test. Further, the discharge variation was 4.1 m / sec, which was 40% of the maximum value.

  Further, the sample No. which is not transferred to the dummy member is out of the scope of the present invention. In Nos. 2 and 3, there were 3 and 5 non-ejection nozzles that did not eject, respectively, and the liquid flow path was blocked.

1 shows a structure of an ink jet head of the present invention, in which (a) is a schematic cross-sectional view, (b) is a plan view on the nozzle hole side, and (c) is a plan view on the pressure generator side. It is a general | schematic fragmentary enlarged view of Fig.1 (a) of this invention. It is a general | schematic fragmentary enlarged view of Fig.1 (a) of this invention. The structure of the conventional inkjet head is shown, (a) is a schematic sectional drawing, (b) is a schematic fragmentary sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Nozzle plate 2 ... Pool plate 3 ... Supply hole plate 4 ... Sealing plate 5 ... Pressure chamber plate 6 ... Vibration plate 7 ... Pressure generator 8 ... Nozzle hole 9 ... nozzle communication hole 10 ... pressure chamber 11 ... supply communication path 12 ... supply hole 13 ... liquid pool

Claims (5)

A plurality of plates each having a through hole or a groove are stacked via an adhesive layer to form a liquid flow path member having a liquid flow path formed therein, and a piezoelectric actuator is bonded to the surface of the liquid flow path member In the method of manufacturing an inkjet head, the adhesive is applied to an adhesive transfer sheet made of an elastic body, a dummy member is brought into contact with the adhesive transfer sheet, and the adhesive is applied to the surface of the adhesive transfer sheet. After the ink is transferred to the dummy member, the plate is brought into contact with the adhesive transfer sheet, and the adhesive remaining on the surface of the adhesive transfer sheet is transferred to the plate. Method. The method of manufacturing an ink jet head according to claim 1, wherein the dummy member is larger than the plate. 3. The method of manufacturing an ink jet head according to claim 1, wherein the adhesive is applied to the dummy member twice or less before the adhesive applied to the adhesive transfer sheet is transferred to the plate. . The adhesive is applied to any one of a pair of plate contact surfaces that contact each other when the plurality of plates are stacked, and the adhesive is not applied to the other plate contact surface. 4. A method for producing an ink jet head according to any one of 3 above. The method for manufacturing an ink jet head according to claim 1, wherein the adhesive layer has a thickness of 0.3 to 2 μm.

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