JP2007283631A - Liquid discharge head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharge head for bonding an orifice plate to a head body with an adhesive, wherein an adhesive is prevented from flowing into a head flow path and ink resistant reliability is achieved as well. <P>SOLUTION: The liquid discharge head is provided in which a UV-curable adhesive is transferred on a head body and an orifice plate is bonded thereto, wherein the adhesive is previously irradiated with trace amounts of UV rays before transferring and irradiated so as to have a partially different exposure dose of the UV rays, and the adhesive is prevented from flowing and adherence reliability is also achieved by firstly irradiating an entire region of the adhesive to be transferred with UV rays, and secondly partially irradiating the resulting adhesive with UV rays. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording head used in printers, video printers, and the like as output terminals of copying machines, facsimiles, word processors, host computers and the like. In particular, it has a substrate on which a heating element (electrothermal conversion element) that generates thermal energy as ink ejection energy is formed, and ink for recording is ejected as a flying droplet from an ejection port (orifice) and adheres to the recording medium. It is related with the liquid discharge head which records by making it.

  Note that “recording” in the present invention includes not only forming an image having a meaning such as a character or a figure on a recording medium but also forming an image such as a pattern having no meaning.

  Conventionally, the method of recording using a liquid discharge head is non-impact recording, with low noise, high density, high-speed printing possible, maintenance is relatively easy and can be maintenance-free, etc. In recent years, it has been widely used.

  An example of this type of conventional liquid discharge head will be described with reference to FIG.

  The liquid discharge head shown in FIG. 7 includes a heating element 1005 that is an energy generation element that generates energy for discharging ink, a substrate 1001 in which a plurality of grooves constituting the ink flow path 1006 are provided in parallel, and ink supply A top plate 1002 having a mouth, and an orifice plate 1004 formed at a position where the orifice 1012 for ejecting ink is connected to the liquid channel 1006 are bonded to the end surfaces of the substrate 1001 and the top plate 1002. Have.

  The orifice 1012 formed in the orifice plate 1004 is very fine, and the orifice 1012 is one of the important factors that influence the ejection characteristics of the liquid ejection head. That is, the orifice plate 1004 of the liquid ejection head is excellent in workability because the fine orifice 1012 is formed, and needs to have good ink resistance because it is in direct contact with ink.

  The orifice plate and the head body are joined using an adhesive. As the adhesive, a thermosetting type, UV curable type, heat, or UV combined type curable adhesive is used. After the adhesive is transferred to the orifice plate or the head body and bonded together, heat is applied or UV is applied. The adhesive is cured by irradiating light to complete the bonding.

As another conventional example, Patent Document 1 can be cited.
JP 2003-237073 A

  However, the conventional liquid discharge head has the following problems.

  When the adhesive is transferred to the orifice plate or the head main body and bonded, the transferred adhesive flows along the edge of the flow path wall of the head main body and flows into the flow path. The adhesive that has flowed in accumulates at the rear end of the flow path wall and has a shape like a match rod, and further blocks the flow path and affects the discharge. In addition, when the adhesive flows into the heater surface, it is difficult for the heat of the heater to escape, which affects the durable life of the heater. In addition, when there is a movable member on the heater, the gap between the heater and the movable member is filled with an adhesive, and the heater and the movable member do not function, and good discharge cannot be performed.

  There is a method to prevent the adhesive from flowing by changing the viscosity of the adhesive, but if the viscosity is increased, it is difficult to reduce the thickness of the adhesive itself. As a result, a large amount of the adhesive enters the front end of the flow path, and this also makes it impossible to perform good discharge.

  In the method of using UV curing type or UV, heat combined curing type adhesive, transferring the light after deteriorating the fluidity by irradiating the entire surface with UV light and starting the curing reaction, bonding The reliability (ink resistance) is lowered, and the ink oozes out to the adhesive interface between the orifice plate and the head main body and mixes colors or affects ejection. Even if the irradiation amount of UV light was controlled, it was difficult to achieve both the elimination of the adhesive entering the flow path and the securing of the adhesive reliability. In addition, if there is a portion that does not irradiate with UV light in the method of transferring and creating a portion that does not irradiate with UV light, the adhesive will enter the flow path and affect the ejection.

  Accordingly, the present invention provides a liquid ejection head that ensures ejection failure and adhesion reliability due to an adhesive that flows in a large amount into a flow path when an orifice plate and a head body are bonded together and cured. With the goal.

  Each of the ink flow paths includes an energy element that generates energy used for ejecting ink, and a plurality of ink flow paths arranged in parallel to each other at a head body that opens at an end surface and a portion corresponding to each ink flow path. In the liquid discharge head to be bonded after transferring the UV curable adhesive or heat and UV combined curable adhesive to the head body with an orifice plate that has an orifice communicating with the path, there are parts with different irradiation amounts irradiated with UV light The adhesive is transferred and bonded.

(Function)
Create a part irradiated with a minute amount of UV light and a part irradiated with a minute amount of UV light on the adhesive, and then transfer and paste them together. Since UV light is irradiated to the entire area of the adhesive to be transferred, the fluidity of the adhesive is deteriorated, and a large amount of adhesive can be prevented from entering the flow path. Compared to the part that was irradiated with a very small amount of UV light and transferred to the entire area of the adhesive, there is also a part that was irradiated with a very small amount of UV light. Will block to some extent. In addition, since there is a portion irradiated with an extremely small amount of UV light, it can be bonded while maintaining the adhesiveness of the adhesive. As a result, a large amount of adhesive can be prevented from entering the flow path, and adhesion reliability can be ensured.

  In the present invention, UV light is preliminarily applied to an adhesive for joining an orifice plate and a head body, and then transferred. By dividing the UV light irradiation into two stages, it is possible to create an adhesive with parts with different irradiation amounts. Since the entire area is irradiated with UV light, the fluidity of the adhesive is improved. Therefore, it was possible to prevent a large amount of adhesive from flowing into the flow path, perform good discharge, and greatly improve the yield of the liquid discharge head. In addition, since there is a part where the UV light is irradiated in the adhesive agent, adhesion reliability (ink resistance) can be secured, and color mixing and ink leakage due to ink seepage from the adhesive interface are prevented. I was able to.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  In the present embodiment, as shown in FIG. 1, a photosensitive resin is patterned on a substrate (11) provided with an energy element for discharging a liquid to form a flow path wall and a liquid chamber frame. A head body (13) was formed by bonding an ink supply port and a top plate (12) forming a part of the flow path above the flow path wall with an adhesive.

  From the viewpoint of processability and ink resistance, the orifice plate (15) was formed with an orifice (14) by laser processing using polysulfone. Further, in order to prevent the adhesive from flowing into the orifice at the time of joining to the head body, a projection (16) is provided on the orifice plate joining surface. These protrusions were also formed by laser processing.

  As the adhesive, a UV / heat combination curing type cationic polymerization type epoxy adhesive was used. In order to completely cure the UV curable adhesive, it is necessary to irradiate a large amount of UV light through the orifice after the orifice plate and the head body are bonded together. Since this has an adverse effect on the water repellent applied around the orifice, this time, UV and heat curing type adhesive was used.

  FIG. 2 shows a method for forming an adhesive thin film. The PET film (22) is laminated on the Si wafer (21), and about 10 g of the adhesive (23) is applied on the PET film. The spin coater is rotated at 5000 rpm for 300 to 400 sec, and the thickness is about A 3 μm adhesive was formed.

  FIG. 4 shows the photomask used this time. The lower half of the photomask was irradiated with UV light over the entire area, and the upper half was partially irradiated with UV light. The portion not irradiated with UV light was surrounded by the portion irradiated with UV light, and each size not irradiated with UV light was made as small as 5 × 5 μm. Further, by using a mask pattern in a regular and larger area than the transfer area of the head main body, accurate transfer positioning of the adhesive after UV irradiation and the head main body is unnecessary.

  Next, UV light was irradiated to the adhesive on PET as shown in FIG. First, the PET coated adhesive film is expanded and fixed. Next, a photomask (33) that partially cuts UV light was pressed against and adhered to the PET film side opposite to the adhesive surface, and UV light was irradiated through the photomask. A condenser lens (32) was attached to the tip of the UV fiber (31) so that the irradiation intensity in the irradiation area was uniform, and the UV light was irradiated under the conditions of an irradiation intensity of 15 mW / cm 2 and a time of 5 to 10 Sec.

  When the irradiation is completed, the photomask is once lifted to release contact with the PET film. As shown in FIG. 5, the PET film is slid by half the distance of the photomask, the photomask is lowered again, and is brought into close contact with the PET film. Thereafter, the second UV light was irradiated to complete the UV irradiation. By irradiating UV light to the entire transfer area at the first time and partially irradiating UV light at the second time, the entire area of the transfer is irradiated with UV light, and an adhesive having a portion with a different irradiation amount is present. I was able to produce it.

  Thereafter, the photomask is raised, and the PET film with adhesive (34) is moved to the adhesive transfer portion of the head body and lowered. The descending point was set so that the distance between the head body and the adhesive was about 1 mm.

  As shown in FIG. 6, the rubber roller (51) was rotated on the PET film under the conditions of a load of about 300 gf and a speed of about 10 mm / Sec. Then, the PET film was raised and peeled off from the head body to complete the transfer of the adhesive. The thickness of the adhesive transferred to the head body is 1.5 μm, which is about half of the thickness spin-coated on PET.

  The head main body to which the adhesive is transferred is brought into contact with the orifice plate in a predetermined positional relationship, and thereafter, the pressure bonding is performed with a load of about 3 kgf. Finally, in order to accelerate the curing of the epoxy adhesive, it was cured by heating at 120 ° C. for 1 hour or more while maintaining the pressure-bonded state to complete the joining.

1 is a schematic configuration diagram of an inkjet head according to an embodiment of the present invention. The thin film formation schematic of the adhesive agent of the Example of this invention. Schematic which irradiates UV light to the adhesive agent of the Example of this invention. The photomask schematic diagram which irradiates UV light partially to the adhesive agent of the Example of this invention. 1 is a schematic diagram of a two-stage UV light irradiation method according to an embodiment of the present invention. Schematic which transfers an adhesive agent to the head main body of the Example of this invention. 1 is a schematic diagram of a configuration of a conventional inkjet head.

Explanation of symbols

11 Si substrate
12 Top plate
13 Head body
14 Orifice
15 Orifice plate
16 Orifice plate convex
21 Si wafer
22 PET film
23 Adhesive
31 UV optical fiber
32 condenser lens
33 Photomask
34 PET film with adhesive
51 Transfer roller

Claims (6)

  Each of the ink flow paths includes an energy element that generates energy used for ejecting ink, and a plurality of ink flow paths arranged in parallel to each other at a head body that opens at an end surface and a portion corresponding to each ink flow path. A liquid discharge head that uses a UV curable adhesive or a combination of heat and UV curable adhesive for the head body with an orifice plate that has an orifice that communicates with the path. The liquid discharge head is characterized by transferring and bonding the adhesive in which the portions irradiated with UV light are different from each other.   First, the entire area of the transferred adhesive is irradiated with UV light, and secondly, the adhesive irradiated with UV light is transferred to a part of the transferred adhesive. The liquid discharge head described in 1. First, UV light is irradiated to a part of the transferred adhesive, and secondly, the adhesive irradiated with UV light is transferred to the entire area of the transferred adhesive. The liquid discharge head described in 1.   Of the adhesive area to be transferred, the adhesive area of the part irradiated with more UV light is less, and the adhesive area of the part irradiated with UV light is larger, smaller or equal to the adhesive area. The liquid discharge head according to claim 1, wherein the liquid discharge head is a liquid discharge head.   5. The liquid discharge head according to claim 1, wherein an adhesive in which portions having different irradiation amounts irradiated with UV light are regularly arranged in the transferred adhesive is transferred. .   6. The liquid discharge head according to claim 1, wherein the adhesive surrounding the portion irradiated with less UV light is surrounded by the portion irradiated with more UV light. .

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