JPH0811314A - Manufacture of ink jet printing head - Google Patents

Abstract

PURPOSE:To stably obtain the bonding properties of a head substrate and a vibration plate, to prevent the generation of the deterioration of quality and to easily realize the supply and emission of ink in the manufacture of an ink jet printing head. CONSTITUTION:In a substrate heating process A, a head substrate 12 made of a thermoplastic resin is preheated to its thermal deformation temp. or lower and, in a vibration plate heating process B, a vibration plate 14 made of a thermoplastic resin is preheated to about welding temp. thereof. In a welding process C, the head substrate 12 and the vibration plate 14 are pressed and welded by a first welding member 22 heated to the thermal deformation temp. or lower on the contact side with the head substrate thereof and a second welding member 24 heated to the welding temp. or higher on the contact side with the vibration plate thereof.

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 print head used in printers, facsimiles, plotters and the like, and more particularly to a method for manufacturing a resin ink jet print head.

[0002]

2. Description of the Related Art Conventionally, there is known an ink jet print head which prints by ejecting ink from a nozzle hole and adhering it to a recording medium without bringing the head into contact with the recording medium. Among these inkjet printheads, there is a type that uses a piezoelectric element that vibrates when a voltage is applied to change the volume of a pressure chamber that temporarily stores ink to suck and eject the ink.

FIG. 3 shows an example of an ink jet print head. The head substrate 50 of the inkjet print head is made of glass material, resin, or the like. When the material of the head substrate 50 is a glass material, by etching or the like,
In the case of resin, an ink flow path communicating with an ink tank (not shown) is formed by molding. This flow channel is formed in an open channel shape and has a common ink flow channel 52, a plurality of pressure chambers 54 communicating with the common ink flow channel 52, and the like. The pressure chamber 54 is provided as a part of the flow path.
In order to prevent the ink from flowing back from the pressure chamber 54 to the common ink flow channel 52 side when the ink is ejected due to the change in the volume of the ink chamber, the ink sandwiching path 56 which is much narrower than the pressure chamber 54 allows the common The ink flow path 52 and the pressure chamber 54 are communicated with each other. Further, on the other end side of the pressure chamber 54, a nozzle channel 60 communicating with a nozzle hole 58 for ejecting ink is formed. The width of the nozzle flow path 60 is also narrower than that of the pressure chamber 54 to improve ink ejection pressure and ejection stability. And the head substrate 5
A vibration plate 62 having a metal film 62b as an electrode is joined to one surface of a base 62a such as glass or resin film on the surface of the pressure chamber 54 on which the pressure chamber 5 is formed.
The piezoelectric elements 64 are arranged at the positions corresponding to 4, respectively. Further, each piezoelectric element 6 is provided on the upper surface of the piezoelectric element 64.
A flexible cable 66 in which a signal line for applying a drive voltage is patterned is arranged on the wiring 4. Each piezoelectric element 6 of the inkjet print head configured as described above
4 independently vibrates in response to the voltage applied via the flexible cable 66, and locally vibrates the corresponding portion of the diaphragm 62. The vibration is transmitted to the pressure chamber 54 and changes the volume of the pressure chamber 54. Then, due to this volume change, a desired amount of ink is ejected from the nozzle hole 58, and printing is performed on the recording medium.

When manufacturing the ink jet print head as described above, the channels (common ink channel 52, pressure chamber 54, ink sandwiching channel 56, nozzle hole 58, nozzle channel 60) formed in the shape of an open channel are formed on the surface. The vibrating plate 62 is adhered to the head substrate 50 having the above (1) using a predetermined adhesive or solvent. That is, by covering the diaphragm 62 with the diaphragm 62, a tunnel-shaped ink flow path is formed.

Since a plurality of ink channels as described above are formed on the head substrate 50 at a pitch of about 1.5 mm, it is extremely difficult to apply an adhesive or a solvent while avoiding the channel section. Difficult to do. Then, for example, Japanese Patent Laid-Open No. 4-27
No. 554, a method of manufacturing an ink jet print head in which a solvent of a predetermined component is applied evenly and thinly on a bonding surface of a vibration plate 62 by a spinner device or the like, and the head substrate 50 and the vibration plate 62 are bonded by a pressure device. It is shown.

[0006]

However, in the conventional manufacturing method, since the adhesive is evenly applied to the ink flow passage portions such as the common ink flow passage 52 and the pressure chamber 54, the ink is not used when the ink jet print head is used. However, there is a problem in that the ink comes into direct contact with the adhesive and the adhesive is eluted by the ink to deteriorate the quality of the ink. In addition, the cured adhesive may be peeled off by the ink to block the flow path, or the adhesive may flow into the flow path when the head substrate 50 and the vibration plate 62 are bonded to each other to narrow or block the flow path. Occurs, which hinders good ink ejection.
In particular, the problem of clogging of the flow path is likely to occur in a narrow flow path such as the ink narrowing path 56 and the nozzle flow path 60, and ink may not be ejected at all.

Further, in the case of a large-sized ink jet print head such as a line type, there is a problem that air bubbles are apt to be entrained when the adhesive is applied to the diaphragm, and the air bubbles cause defective adhesion and ink leakage.

The present invention has been made in view of the above conventional problems, and an object thereof is to obtain a stable bondability between a head substrate and a vibration plate, and to facilitate ink supply and ink ejection without quality deterioration. An object of the present invention is to provide a method of manufacturing an inkjet printhead that can be realized.

[0009]

In order to achieve the above object, in the method of manufacturing an ink jet print head of the first structure, a vibration plate is vibrated by applying a voltage to a driving element and formed on a head substrate. In a method for manufacturing an inkjet print head that ejects ink from a nozzle hole and prints on an object to be printed, a substrate heating step of preheating a head substrate made of a thermoplastic resin to a thermal deformation temperature or lower,
A vibrating plate heating step of preheating a vibrating plate made of a thermoplastic resin around the fusing temperature, and heating the first substrate contact side to a temperature below the thermal deformation temperature and the fusing plate contact side above the fusing temperature. And a fusion step of fusion-bonding the head substrate and the vibration plate with each other by the heated second fusion body.

A second method of manufacturing an inkjet print head is the same as the first method of manufacturing an ink jet print head, except that the cylindrical or block-shaped first fused body and the cylindrical or block-shaped first fused body are used. Second
It is characterized in that the head substrate and the vibrating plate are pressed and fused by a combination with the fused body.

[0011]

According to the method of manufacturing the ink jet print head of the first structure of the present invention, the head substrate made of the thermoplastic resin is preheated to a temperature not higher than the thermal deformation temperature in the substrate heating step, and the thermoplastic resin is heated in the vibrating plate heating step. A resin diaphragm is preheated to around the fusion temperature. The head substrate and the vibrating plate are formed by a first fusion body whose head substrate contact side is heated to a thermal deformation temperature or lower in the fusion step and a second fusion body whose vibration plate contact side is heated to a fusion temperature or higher. And fusion bonding.
Therefore, it is possible to bond the head substrate and the diaphragm without using an adhesive, and it is possible to eliminate problems such as ink quality deterioration and ink clogging due to the adhesive, and to heat the head substrate side below the thermal deformation temperature. Therefore, the head substrate and the vibration plate can be bonded to each other without deforming the head substrate or the flow path.

Further, according to the method of manufacturing the ink jet print head having the second structure, the head substrate is formed by combining the cylindrical or block-shaped first fusion body and the cylindrical or block-shaped second fusion body. Since the vibration plate is pressed and fused, the pressure bonding state can be selected according to the shape of the head substrate, and the bonding failure can be avoided.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an ink jet print head 1.
FIG. 6 is a process explanatory view illustrating a bonding process between the head substrate 12 of 0 and the vibration plate 14;

The characteristic feature of this embodiment is that the head substrate made of a thermoplastic resin and the diaphragm are joined by heat fusion.

The head substrate 12 is made of, for example, a thermoplastic resin such as polysulfone, polyether sulfone, or polycarbonate. The head substrate 12 undergoes a predetermined resin molding process, and a common ink channel 52 as shown in FIG. A pressure chamber 54, an ink sandwiching path 56, and the like are formed. Such a head substrate 12 is conveyed by a continuous conveyor 18 having a continuous preheating furnace 16. The continuous preheating furnace 16 is heated to a predetermined temperature by a heating means such as a heater 16a, and the head substrate 12 as an object to be heated is heated by the continuous preheating furnace 16a.
Preheat to a predetermined temperature while passing through the inside (substrate heating step A). When the head substrate 12 is made of polysulfone, it is preheated at 170 ° C. or less, for example, in consideration of the heat deformation temperature of polysulfone of 170 to 180 ° C.
As for the temperature of the head substrate 12, it is necessary to heat the entire head substrate 12 uniformly in order to perform uniform fusion in the fusion process described later. Therefore, it is preferable that the heating means of the continuous preheating furnace 16 is arranged so as to surround the head substrate 12, and in this embodiment, the heating means is arranged on the upper and lower surfaces of the continuous conveyor 18, and the transfer surface of the continuous conveyor 18 is made of metal as shown in the drawing. It is desirable to use a mesh or to support a part of the head substrate 12 so that the continuous preheating furnace 16 is conveyed in the air.

On the other hand, the diaphragm 14 made of thermoplastic resin such as polysulfone, polyether sulfone or polycarbonate is conveyed to the diaphragm heating step B. Diaphragm 1
4 is supplied in a roll shape in consideration of ease of handling and the like, and is preheated to a predetermined temperature through the continuous preheating furnace 20 similar to the substrate heating step A. The preheating temperature of the diaphragm in the diaphragm heating step B is 220 ° C. considering that the fusion temperature is 200 to 230 ° C. when the diaphragm material is polysulfone.
The degree is desirable. In addition, it is desirable to select the same material for the head substrate 12 and the diaphragm 14 in order to favorably perform the later-described fusion bonding.

When the head substrate 12 and the vibrating plate 14 are preheated to a predetermined temperature, they are conveyed to the fusing step C while maintaining the preheating temperature. In the fusing step C, a pair of fusing bodies are arranged, and the head substrate 12 and the vibrating plate 14 are sandwiched by the fusing bodies to press them, and the fusing is performed by utilizing the thermal deformation of the vibrating plate 14. That is, the first fusion-bonded body having a roll shape that comes into contact with the head substrate 12 is lower than the thermal deformation temperature of the head substrate 12 (170 ° C. or lower in the case of polysulfone).
Then, the second fusion-bonded body having a roll shape that comes into contact with the vibration plate 14 is heated to the fusion temperature of the vibration plate 14 or higher (230 ° C. or higher in the case of polysulfone). The first fused body 2
2. The second fused body 24 is a heating means 22a, 24 such as a heater.
The temperature is constantly controlled to a predetermined temperature by a.

When the first and second roll-shaped fusion bodies 22 and 24 are fused together, the fusion is carried out sequentially from the end portion of the head substrate 12, so that it is difficult for bubbles to enter during fusion and the head substrate Good joining of 12 and the diaphragm 14 can be performed. In the case of a roll-shaped fused body, the surface of the fused body is made elastic so that the thickness of the head substrate 12 or the vibration plate 14 can be absorbed, or the fused body is vertically moved in the figure depending on the thickness. It is desirable to be able to swing.

The head substrate 12 integrated with the vibrating plate 14 in the fusing step C is conveyed to the cooling step D and is heated to a predetermined temperature, for example, the thermal deformation temperature (17) or lower when the material is polysulfone.
Stabilize the fusion by cooling to 0 ° C or less). When cooling, it may be done by natural cooling or air blow,
By using the cooling die 26 having the forced cooling means 26a such as a fan, it is possible to maintain the shape of the head substrate 12 and the diaphragm 14 in the shape at the time of fusion bonding, or to correct the shape to the final shape. Further, when it is known that warpage or the like occurs when the temperature of the head substrate 12 drops to room temperature, the correction may be performed in consideration of the warpage.

Next, the electrode 28 for driving the piezoelectric element is bonded to the back surface side of the diaphragm 14 (electrode bonding step E). The electrodes for driving the piezoelectric element are, for example, the head substrate 12 and the diaphragm 14.
Any material may be used as long as it is more rigid and conductive than the resin of the above material, but an aluminum film having a linear expansion coefficient close to that of the resin is desirable. The electrode 28 is already adhered to the head substrate 12 because the diaphragm 14 is already bonded to the head substrate 12 and the ink flow path is not blocked. Therefore, the adhesive 28 is applied to the sheet-shaped electrode 28 by using the adhesive application device 30 or the like. And is adhered to the vibration plate 14 using the pressure rollers 32a and 32b.

The electrodes may be formed by directly forming an aluminum film on the vibration plate 14 by vapor deposition, sputtering or the like. In this case, the aluminum film can be formed before the diaphragm 14 is preheated.

Then, as a final step, the punching die 34
The excess vibration plate 14 around the head substrate 12 is cut by a and 34b (head separation step F), the inkjet print head 10 is separated, and the step of joining the head substrate 12 and the vibration plate 14 is completed.

As described above, since the head substrate 12 and the vibrating plate 14 can be joined to each other without using an adhesive, problems such as clogging of the ink flow path and deterioration of the quality of the flowing ink are caused. Can be resolved.

In this embodiment, FIGS. 1 and 2A are used.
As shown in FIG. 2, an example using a cylindrical fusion-bonding mold is shown. For example, as shown in FIG.
-1, 24-1 may be used, or as shown in FIG. 2C, the cylindrical first fusion body 22 and the block-shaped second fusion body 24-
Even if 1 and 2 are combined, the same effect as that of the above-described embodiment can be obtained. As shown in FIGS. 2 (a) and 2 (c), in the case of the cylindrical fusion-bonding type or the combination of the cylindrical shape and the block-shape, since the fusion can be performed while removing the bubbles, the head substrate area is reduced. It is suitable for manufacturing a relatively large line type inkjet printhead, and as shown in FIG. 2B, the combination of block-shaped fusion members can be fused by one pressing operation in a short time. It is suitable for manufacturing a serial type inkjet printhead having a relatively small size. Further, as shown in FIG. 2D, the block-shaped fused body is formed into a shape of the head substrate 12 '(for example, the head substrate is bent in a dogleg shape, and an ink flow path is formed inside the bent portion). The head substrate having a complicated shape and the diaphragm can be easily joined to each other.

[0026]

According to the first invention of the present application, the head substrate made of a thermoplastic resin is preheated to a temperature not higher than the thermal deformation temperature in the substrate heating step, and the vibrating plate made of the thermoplastic resin in the vibrating plate heating step. Is preheated around the fusion temperature. Then, in the fusion process, the head substrate contact side is heated to a temperature not higher than the thermal deformation temperature.
The head substrate and the vibration plate are fusion-bonded to each other by the fusion-bonding body and the second fusion-bonding body in which the diaphragm contact side is heated to a fusion-bonding temperature or higher. Therefore, it is possible to bond the head substrate and the diaphragm without using an adhesive, and it is possible to eliminate defects such as ink quality deterioration and ink clogging due to the adhesive, and to heat the head substrate side to a temperature below the thermal deformation temperature. Because
It is possible to manufacture an inkjet print head that can easily realize the bonding between the head substrate and the diaphragm without deforming the head substrate or the flow path.

Further, according to the second invention of the present application, the head substrate and the vibration plate are formed by combining the cylindrical or block-shaped first fusion body and the cylindrical or block-shaped second fusion body. Since pressure and fusion are performed, it is possible to select the pressure bonding state according to the shape of the head substrate, and reduce the entrainment of air bubbles when bonding the head substrate and the diaphragm, and stably bond the head substrate and the diaphragm. It is possible to manufacture an inkjet printhead having a property.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a joint process between a head substrate and a diaphragm in a method for manufacturing an inkjet print head according to the present invention.

FIG. 2 is an explanatory view illustrating the shape of a fused body in the method for manufacturing an inkjet print head according to the present invention.

FIG. 3 is an explanatory diagram illustrating a configuration of a general inkjet printhead.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ink jet print head 12 Head substrate 14 Vibrating plate 16 and 20 Continuous preheating furnace 22 1st fusion body 24 2nd fusion body

Claims (2)

[Claims] 1. A method of manufacturing an ink jet print head, comprising: applying a voltage to a driving element to vibrate a vibrating plate to eject ink from nozzle holes formed in a head substrate to print on a printing object; Substrate heating process to preheat the head substrate made of metal to below the heat distortion temperature; Vibration plate heating process to preheat the diaphragm made of thermoplastic resin to around the fusing temperature; A fusion step of fusion-bonding the head substrate and the vibrating plate with a heated first fusion body and a second fusion body whose contact side of the vibration plate is heated to a fusion temperature or higher. A method for manufacturing an ink jet print head, which is characterized. 2. The method for manufacturing an inkjet printhead according to claim 1, wherein the head substrate and the vibration are produced by a combination of the cylindrical or block-shaped first fusion body and the cylindrical or block-shaped second fusion body. A method for manufacturing an inkjet print head, which comprises pressurizing and fusing a plate.