JPH06286146A - Production of ink jet head - Google Patents

Abstract

PURPOSE:To easily bond a flow path substrate and a cover plate, both of which are made of a resin molded piece, and to produce a highly reliable ink jet head at a low cost. CONSTITUTION:A cover plate 3 is mounted on a jig 15 of an ultrasonic bonding device 12 with the contact surface thereof showing up. Thereon, a sheet-form adhesive 2 is laminated and, in this state, an ultrasonic vibration is applied to the cover plate 3 and the sheet-form adhesive 2 through horns 14a, 14b by an ultrasonic vibrator 13 to semi-cure the adhesive to temporarily bond the both to each other. Next, a flow path substrate is laminated on the sheet-form adhesive 2. A short-time ultrasonic vibration is applied to both to securely bond both through the adhesive. An ink pool substrate is contact bonded to the other surface of the cover plate 3, whereby a section of a common ink chamber is formed. By bonding piezoelectric elements opposedly to pressurizing chambers of ink flow paths on the other surface of the ink flow path substrate, an ink jet head is completed. In this manner, bonding can be conducted by ultrasonic vibration without protuberances (energy director). Thus, a high- accuracy bonding surface is not required, and bonding with high sealing properties can be performed in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet head.

[0002]

2. Description of the Related Art In an ink jet head, a cover plate is generally bonded to an upper surface of a flow path substrate having a groove-shaped ink flow path, and a piezoelectric element is attached to the flow path substrate or the cover plate so as to correspond to the ink flow path. It is composed of As the material of the flow path substrate and the cover plate, borosilicate glass or photosensitive glass is used, the ink flow path and the nozzle holes are formed by the etching method, and the flow path substrate and the cover plate are joined by heat fusion. Has been done. However, since these glass materials are expensive and are not easily processed, it has been attempted to replace them with inexpensive and easily processed plastic injection molded products.

When the ink jet head is made of a resin molded product, a bonding method using an adhesive or a solvent is employed, and a method of bonding by ultrasonic vibration is also proposed (Japanese Patent Laid-Open No. 62-62). 234940).

[0004]

As described above, when the ink jet head is made of a resin molded product, the method of joining the flow path substrate and the cover plate poses a problem. When bonding with an adhesive or solvent as in the prior art, the adhesive or the like must be applied only to the bonding points of the resin molded product, making it difficult to apply between fine ink flow paths. It is efficient. Further, the reliability of the inkjet head is lowered, such as blocking of the ink flow path due to the flow-down of the adhesive or the like.

Therefore, a method of joining resin molded products by ultrasonic vibration is introduced. But in this case,
In order to increase the joint reliability of both plates, it is necessary to provide a ridge (energy director) for effectively applying ultrasonic vibration to the joint part of the flow path substrate or the cover plate, but it is not It is difficult to apply such processing to such fine precision parts.

Therefore, an object of the present invention is to make it possible to manufacture a highly reliable ink jet head at low cost by using an inexpensive resin molded product.

[0007]

In order to achieve the above object, the present invention provides a flow channel substrate having an ink flow channel groove and a lid which is contact-bonded to a surface of the flow channel substrate having the ink flow channel groove. In the method of manufacturing an ink jet head in which a plate is formed of a resin molded product, a cover plate and a flow path substrate are laminated via an adhesive layer, and ultrasonic vibration is applied to the flow path substrate and the cover plate so that they are mutually separated. It is designed to be fixed.

In the above means, preferably, the first step of temporarily bonding the adhesive layer to the surface of the lid plate facing the flow path substrate, and the lid plate and the flow path substrate are laminated via the adhesive layer. However, it is desirable to include a second step of fixing both by applying ultrasonic vibration.

The adhesive layer may be made of a sheet adhesive.

[0010]

[Function] When the lid plate and the flow path substrate are laminated via the adhesive layer and then ultrasonic vibration is applied to the both plates to fix them to each other via the adhesive layer, it is possible to firmly bond them in a short time. Stick to.

The adhesive layer is semi-cured by temporary bonding, which is the first step as the step of fixing the lid plate and the flow path substrate to prevent the adhesive from flowing down and forming a gap on the contact surface. In the second step, when ultrasonic vibration is applied to both plates, both plates are firmly fixed.

By using a sheet-like adhesive as the adhesive layer, the step of forming the adhesive layer becomes easier.

[0013]

EXAMPLES Next, as one example of the present invention, a case of manufacturing an on-demand type ink jet head having an arrangement as shown in FIGS. First, the structure of the inkjet head to be manufactured will be described.

As shown in FIGS. 1 and 2, a cover plate 3 is contact-bonded to the flow path substrate 1 via a sheet adhesive 2, and an ink pool substrate 4 is further contact-bonded to the cover plate 3. I am doing it.
Each of the flow path substrate 1, the lid plate 3, and the ink pool substrate 4 is made of an injection molded product of a resin material (polysulfone or the like).

As shown in FIG. 3, the flow path substrate 1 has a disk-like outer shape, and a large number of ink flow path grooves 5 are formed on its upper surface in a substantially centripetal manner. The ink flow channel grooves 5 are arranged in a rhombus in the vicinity of the center, and the tips of the ink flow channel grooves 5 penetrate the flow channel substrate 1 and communicate with the nozzles 10 having ejection ports.

As shown in FIGS. 4 and 5, the cover plate 3 has a disk shape having a uniform thickness, and a large number of tapered ink supply holes (at a predetermined radial position from the center of the disk surface). .. are arranged in a circular shape and at equal intervals. The sheet-like adhesive 2 that is in contact with the outlet of the restriction 6 has through holes 7 ...

A common ink chamber portion 8 is formed inside the ink pool substrate 4, and this common ink chamber portion 8 covers the cover plate 3.
And the common ink chamber I is partitioned and formed.
At the center of the ink pool substrate 4, a tube portion 11 for ink supply is provided.

Flow channel substrate 1, lid plate 3 and ink pool substrate 4
In the state in which the ink flow path substrate 1 and the ink flow path groove 5 of the flow path substrate 1 are stacked and joined, the ink flow path R is defined by being blocked by the adhesive layer made of the sheet adhesive 2. The path R can receive ink from the common ink chamber I via the restriction 6 and the through hole 7, respectively.

Piezoelectric elements 9 for applying energy to the ink supplied into the ink flow path R are attached to the outer surface (lower surface in FIG. 1) of the flow path substrate 1. The tips of the ink flow channel grooves 5 facing the center of the flow channel substrate 1 constitute nozzles 10 ... Which have ejection ports in a direction perpendicular to the plate surface.

The ink supplied from the pipe portion 10 to the common ink chamber I is supplied to each ink flow path R through the restriction 6 and the through hole 7. The ink in the ink flow path is given energy by the vibration of the piezoelectric element 9 and is ejected from the nozzle 10 to perform a printing operation on the recording paper (not shown) in the front.

Next, a method of manufacturing the ink jet head in this embodiment will be described.

First, the facing surface 3a of the cover plate 3 shown in FIG. 4 with the flow path substrate 1 is positioned above and set in the ultrasonic bonding apparatus 12 shown in FIG. The sheet-shaped adhesive 2 having the through holes 8 formed in advance is overlapped on the facing surface 3a of the upper lid plate, and the restriction 6 and the through holes 8 are aligned with each other. The sheet adhesive 2 is made of epoxy resin and has a thickness of 20 to 60 μm.
In order to prevent the ink from flowing into the ink flow path or the like, a sheet having a aging treatment at a temperature of 60 ° C. for 120 hours was used.

The ultrasonic bonding apparatus 12 will be briefly described. Vibration generated by supplying electric power to the ultrasonic vibrator 13 from the outside is propagated by the horn 14a and propagated by another horn 14b. Ultrasonic vibration can be applied to the entire object. A jig 15 is provided so as to face the horn 14b.
The jig 15 and the horn 14b are designed according to the shape of the workpiece, and a cylinder 16 for moving up and down the horns 14a and 14b and the ultrasonic transducer 13 is provided. Therefore, the lid plate 3 to which the sheet adhesive 2 is attached is placed on the jig 15, and the horn 14b is pressed against the sheet adhesive 2 by operating the cylinder 16. Then, the ultrasonic vibrator 13 is operated to apply ultrasonic vibration to the contact surface between the sheet adhesive and the cover plate 3 via the horns 14a and 14b.

Specifically, the cover plate 3 and the sheet-like adhesive 2 are pressed at 200 kPa, and at the same time 20-40.
Ultrasonic vibration of kHz is applied for 0.3 to 0.4 seconds. Then, frictional heat is generated on the joint surface between the two, and the sheet-like adhesive 2 is tentatively joined to the cover plate 3 by utilizing the resulting heat welding (first
Process). By applying ultrasonic vibration under the above conditions, the sheet-shaped adhesive 2 becomes semi-cured.

Next, as shown in FIG. 6, a sheet-like adhesive 2 in which the ink flow path groove surface of the flow path substrate 1 is temporarily joined to the cover plate 3.
To the jig 15 of the ultrasonic bonding apparatus 12 (see FIG. 8). Then, similarly to the first step, the cylinder 16 is operated to apply 200 kP to the flow path substrate 1 and the lid plate 3.
While applying pressure with a, the ultrasonic vibrator 13 is activated to apply ultrasonic vibration of 20 to 40 kHz for 0.3 to 0.4 seconds to completely cure the sheet adhesive 2 and the flow path substrate 1 and the lid. The plate 3 is firmly bonded (second step). Note that FIG.
In the above, the horn 14c having a shape matching the outer shape of the flow path substrate 1 is used. However, if the horn shape can be commonly used in the first step and the second step, it is not necessary to replace the horn in both steps. Absent.

In this way, the lid plate 3 is provided on the upper surface of the flow path substrate 1.
Are joined together to form a large number of ink flow paths R between the plates. The ink pool substrate 4 is further bonded to the upper surface of the cover plate 3 with an adhesive to define and form the common ink chamber I, and the ink supply pipe portion 11 and the nozzle 10 are connected to each other. Finally, the pressurizing chamber 5a provided in the middle of the ink flow path
If the piezoelectric elements 9 are attached to the respective outer surfaces of the opposing surfaces with an adhesive, an inkjet head is completed.

Conventionally, when the flow path substrate 1 and the cover plate 3 are bonded only by the adhesive layer (sheet-shaped adhesive 2), if either of the plates is warped and the adhesion is poor, the bonding will be poor. The reliability was low, and it was necessary to continue to strongly press both plates for a long time (about 2 hours) until the adhesive was completely cured.
However, according to the above-mentioned embodiment, it is possible to completely bond the two plates by curing the adhesive in an extremely short time (several seconds) by utilizing ultrasonic vibration.

Further, according to the present invention, since the joining by the adhesive and the ultrasonic joining are used together, the welding is not dependent only on the heat generation due to the frictional force, the finishing of the joining surface is not required to be highly accurate, and the applied pressure is Is set to be lower than the pressure applied in normal ultrasonic processing, and the ultrasonic wave application time may be short. Since the adhesive is semi-cured in the first step, the adhesive may flow into the restriction or the ink flow path in the second step due to the pressure applied to the flow path substrate 1 and the substrate 3. In other words, they are joined in a state where there is no fear that the supply of ink will be hindered. In this way, the two plates are fixed in a bonded state with a high sealing property that does not create a gap on the joint surface.

As described above, when ultrasonic vibration is applied to both plates through the adhesive layer, the adhesive can be solidified in an extremely short time, so that it can be easily incorporated into a flow work. It plays an important role in shortening the assembly process of the inkjet head. By the way,
In the case of joining with only an adhesive, it takes about 2 hours to completely solidify, whereas in the present invention, joining can be performed in about 5 seconds including the attachment / detachment time.

In this embodiment, the nozzle is provided on the flow path substrate side, and the piezoelectric element is attached on the front surface side of the flow path substrate, and the invention is applied to the ink jet head. However, the present invention is not limited to this. However, the present invention can be applied to all cases in which a resin-made flow path substrate and a lid plate are joined together.

Although a sheet-like adhesive is used as the adhesive layer, a liquid adhesive may also be applied by a screen printing method or the like. Further, the material of the flow path substrate and the lid plate is not limited to polysulfone, and a resin material such as polyarylate having good injection moldability and excellent ink resistance may be adopted. In addition, it is possible to obtain a good bonding state by appropriately changing each condition of ultrasonic bonding according to the bonding conditions of the flow path substrate and the kind of the adhesive.

[0032]

As described above, since the present invention uses both ultrasonic bonding and bonding by means of an adhesive layer, a special ridge (energy director) is provided at the bonded portion as in the prior art. Since it is not necessary to design and the precision of the joint surface does not need to be so severe, it is easy to manufacture a molded product such as a flow path substrate or a cover plate. Then, because the resin materials are not fused only by ultrasonic vibration but are bonded via an adhesive layer, the pressure applied when applying ultrasonic vibration can be lowered, and further, Since the sealing property is high and the application time of ultrasonic vibration is short, it is suitable for being incorporated into a flow work, and contributes to shortening the assembly process of the inkjet head.

Further, if the both plates are joined after the adhesive layer is semi-cured by temporary joining, the adhesive can be prevented from flowing into the flow path and the like, and the reliability is improved. In addition, by adopting a sheet adhesive, it is possible to obtain an inkjet head of excellent quality in a short time, which contributes to lowering the cost of the inkjet head and simplifies the step of attaching the adhesive. In addition to shortening the length, it is possible to prevent the adhesive from flowing into the flow path or the like, so that an inkjet head with high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a completed inkjet head.

FIG. 2 is a bottom view of FIG.

FIG. 3 is a plan view of an ink channel groove surface of a channel substrate.

FIG. 4 is a cross-sectional view showing a state in which an adhesive is attached to the facing surface of the lid plate.

FIG. 5 is a plan view of a facing surface of a lid plate.

FIG. 6 is a cross-sectional view showing a state in which a flow path substrate and a cover plate are bonded together via an adhesive layer.

FIG. 7 is an explanatory diagram showing a first step.

FIG. 8 is an explanatory diagram showing a second step.

[Explanation of symbols]

 1 Channel Board 2 Adhesive Layer (Sheet Adhesive) 3 Lid Plate 5 Ink Channel Groove

Claims (3)

[Claims] 1. A method of manufacturing an ink jet head, comprising a resin substrate and a flow path substrate having an ink flow path groove, and a cover plate that is face-to-face bonded to a surface of the flow path substrate having the ink flow path groove. , The lid plate and the flow path substrate are laminated via an adhesive layer,
A method of manufacturing an inkjet head, wherein ultrasonic vibration is applied to the flow path substrate and the lid plate to fix them to each other. 2. The first step according to claim 1, wherein the adhesive layer is temporarily bonded to a surface of the lid plate facing the flow path substrate, and the lid plate and the lid plate are joined together via the adhesive layer. A second step of stacking a flow path substrate and fixing both by applying ultrasonic vibration. 3. The method for manufacturing an inkjet head according to claim 1, wherein the adhesive layer is made of a sheet adhesive.