JPH10217483A - Manufacture of nozzle plate for ink jet printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge ink stably by a method wherein an ink discharging port is formed by press work from the rear surface of a metallic flat plate member and, thereafter, water repellent coating is applied on the whole of metallic flat plate member, including the inner surface of the ink discharging port, while the coating of an oxide or a metal is applied on the rear surface of the metallic flat plate member. SOLUTION: Holes are made by punching in a metallic flat plate member from a side corresponding to the rear surface 5 of the ink discharging direction, and then burs are removed from an ink discharging surface 3 through grinding and chemical etching whereby an ink discharging port 4, opened cylindrically, is formed. Next, water repellent coating 6 is formed on the whole of the nozzle plate including the ink discharging port 4. In this case, the thickness of the coating can be controlled by the dipping period of time. Subsequently, an oxide film or a metallic film 9 is formed through the method of depositing, sputtering or iron plating from a direction orthogonal to the ink discharging rear surface 5 whereby a nozzle plate for ink jet printer head, in which the entering position of water repellent coating 6 into the inside of ink discharging port 4 is constant, can be obtained.

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 a nozzle plate used in an ink jet printer head, and more particularly to a surface treatment method for imparting water repellency to an ink discharge surface and an inner surface of an ink discharge hole.

[0002]

2. Description of the Related Art Conventionally, ink jet printers, which are one type of non-impact printers in the field of computer output applications, mainly use aqueous inks such as aqueous inks in which a water-soluble dye is dissolved and aqueous inks in which organic or inorganic pigments are dispersed in water. After ink is supplied and filled into the ink flow path, a method of ejecting and printing as ink droplets by applying mechanical heat by a piezoelectric element or instantaneously applying heat to the ink to explosively expand the ink and printing is mainstream. .

Generally, in order to stably and straightly eject ink droplets, adhesion of residual ink around ink ejection holes of a nozzle plate is prevented, and the ink ejection surface of the nozzle plate is chemically stable with respect to ink. It is required to be.

As a means for achieving this, it has been proposed to form a water-repellent film on the ink ejection surface, and as a material exhibiting water repellency, a silicone resin, a fluororesin, or a Teflon eutectoid plating film is known. ing.

However, when the above-described water-repellent film is formed, the position of the meniscus of the ink is determined by the amount of the water-repellent film entering the inside of the ink ejection hole, which greatly affects the ink ejection characteristics. Are known. Therefore, it is required that the amount of the water-repellent coating that enters the ink ejection holes be precisely controlled and that the meniscus position be kept constant. That is, if the penetration amount of the water-repellent coating is close to the ink ejection surface, erroneous ejection is likely to occur due to mechanical vibration from the outside, and if the penetration amount is far from the ink ejection surface, after the ink droplet is ejected, it becomes easy to entrap bubbles, Discharge characteristics become unstable. Furthermore, the meniscus position determined by the amount of penetration of the water-repellent film greatly depends on parameters such as the size of the ink flow path, the thickness of the nozzle plate, the size of the ink ejection hole, the type of ink, the driving method, and the driving force. The position is variable, and a mass production technology is required.

[0006]

As one method, for example, a photosensitive resin film is pressed against the ink ejection back surface of a nozzle plate against JP-A-7-125220, and a part of the film is pressed into the ink ejection holes and cured. A method of performing Teflon eutectoid plating and thereafter removing the film is disclosed, but in this method, it is difficult to accurately control the indentation amount in order to adjust the indentation amount of the photosensitive resin film with the temperature, and furthermore, When the diameter of the ink ejection hole is reduced to increase the printing resolution, the process becomes very difficult, for example, it becomes difficult to push the photosensitive resin film, and the mass productivity is poor.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and a water-repellent film is coated on an ink ejection surface. An object of the present invention is to provide a method for manufacturing a nozzle plate for an ink jet printer head which is excellent in mass productivity.

[0008]

In order to achieve the above object, the method described below is employed in the method of manufacturing a nozzle plate for an ink jet printer head according to the present invention. The method of manufacturing a nozzle plate for an ink jet printer head according to claim 1 of the present invention comprises the steps of: punching an ink ejection hole from the back surface of a metal plate member by pressing; and forming a water-repellent coating on the entire metal plate member. The method includes a step of coating and a step of forming an oxide or metal film on the back surface of the metal plate-shaped member.

According to a second aspect of the present invention, there is provided a method of manufacturing a nozzle plate for an ink jet printer head according to the first aspect of the invention, wherein the ink ejection holes are formed by pressing from the back surface of the metal plate member. It is characterized in that the step of opening is plastic working by a punch comprising a cylindrical front end portion and a conical rear end portion.

According to a third aspect of the present invention, there is provided a method of manufacturing a nozzle plate for an ink jet printer head according to the first aspect of the invention, wherein an oxide or a metal is formed on the back surface of the metal plate member. The method is characterized in that the process is a method by vapor deposition, sputtering, or ion plating.

(Operation) In the method of manufacturing a nozzle plate for an ink jet printer head according to the present invention, first, an ink discharge hole is formed by punching from the back surface of a metal plate member. This process is a plastic working using a punch consisting of a cylindrical front end portion and a conical rear end portion, and is formed by a cylindrical opening portion on the ink ejection surface and a funnel opening portion on the ink ejection back surface by this process. An ink ejection hole is formed. Thereafter, the entire nozzle plate including the inner surface of the ink ejection hole is coated with a water-repellent coating.

Next, an oxide or metal film is formed by a method such as vapor deposition, sputtering, or ion plating from the direction perpendicular to the back surface of the metal plate member, that is, the back surface of the ink ejection. It is known that the oxide or metal formed at this time exhibits hydrophilicity. Normally, the diameter of the ink ejection hole is as small as 50 μm or less at the portion opened in a cylindrical shape on the ink ejection surface. Therefore, in the above-described film forming method, the film can be formed on the portion opened in the funnel shape on the ink ejection back surface. However, no film is formed on a portion of the ink ejection surface which is open in a cylindrical shape. Therefore, the water-repellent coating is exposed only on the ink ejection surface and the cylindrical opening inside the ink ejection to exhibit water repellency, whereas the funnel-shaped opening on the ink ejection back surface and the ink ejection back surface is made of oxide or metal. The film is formed and becomes hydrophilic.

According to the above-described method, the portion of the ink ejection surface which is cylindrically opened depends on the shape of the punch at the time of press working. The position where the water-based coating is exposed, that is, the penetration amount of the water-repellent coating is variable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a nozzle plate for an ink jet printer head according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is an enlarged schematic sectional view showing the structure of the nozzle plate for an ink jet printer head according to the first embodiment of the present invention, in which the ink discharge holes are enlarged.
The ink jet printer head nozzle plate has a water-repellent coating 6 coated on the entire nozzle plate, that is, the ink ejection surface 3, the ink ejection hole 4 inner surface, and the ink ejection back surface 5.
Further, an oxide or metal film 9 is laminated on the water-repellent coating 6 covering the ink discharge back surface 5 and the funnel-shaped opening 8.

FIG. 1 is a perspective external view of a thin plate-shaped nozzle plate 2 for an ink jet printer head to which a manufacturing method according to an embodiment of the present invention is applied. FIG. 2 is a cross-sectional view of a punch having a cylindrical front end portion and a conical rear end portion used for punching an ink ejection hole from the back surface of a metal flat plate member according to the first embodiment of the present invention. It is a figure, which is made of a super hard material represented by tungsten carbide. Furthermore, the length of the cylindrical tip portion 21 is
Since the length becomes the same as the entry position inside the ink ejection hole 4, adjustment is made in advance to match the ink ejection characteristics. 3 to 6 show a method of manufacturing a nozzle plate for an ink jet printer head according to a first embodiment of the present invention. FIG. 3 is a sectional view of a metal plate member, and FIGS. It is the process sectional drawing expanded. Hereinafter, description will be given with reference to FIG. 1 and process cross-sectional views of FIG. 3 to FIG.

In order to manufacture the nozzle plate for an ink jet printer head according to the present invention, a length 3 shown in FIG.
A hole shown in FIG. 2 is punched from the side of the flat metal member 1 having a thickness of 0 mm, a width of 15 mm, and a thickness of 0.1 mm, which corresponds to the ink ejection back surface 5. The material of the metal plate-like member 1 is stainless steel, but other materials such as nickel, nickel alloy and iron-based alloy may be used. The length of the cylindrical tip portion 21 of the punch is 10 microns and the diameter is 40 microns.

In this process, burrs are generated on the ink discharge surface 3, but are removed by polishing and chemical etching of the ink discharge surface 3.

As shown in FIG. 4, the diameter of the ink discharge surface 3 of the ink discharge hole 4 is 40 microns, the diameter of the ink discharge rear surface 5 is 100 microns, and the length of the cylindrical opening 7 is 10 as shown in FIG. Micron ink ejection holes 4 are formed. Although one ink ejection hole 4 is illustrated in the figure,
By arranging the punches shown in FIG. 2 in series, it is possible to form many ink ejection holes 4 at a time as shown in FIG.

Next, as shown in FIG. 5, Teflon eutectoid plating is performed to form a water-repellent coating 6 on the entire nozzle plate 2.

This plating process can be performed by any of electroplating and electroless plating. In this embodiment, electroless plating called Nimflon (trade name) (Uemura Kogyo Co., Ltd.) is employed.

The plating thickness of the Teflon eutectoid plating can be controlled by the immersion time in the plating solution, and was set to 3 μm in the embodiment of the present invention. Further, it is preferable to perform a heat treatment at 350 to 400 ° C. in order to increase the hardness of the surface of the Teflon eutectoid plating and increase the wear resistance.

It has been confirmed by electron microscopic observation that the coating film of this Teflon eutectoid plating contains fluorine resin fine particles having a diameter of 0.2 μm uniformly dispersed in the range of 20 to 30 vol%.

The water-repellent coating 6 may be made of a material other than Teflon eutectoid plating, and may be a fluororesin or a silicone resin.

Next, a chromium film is formed by vapor deposition from a direction perpendicular to the ink discharge back surface 5. The film thickness was 0.2 microns. By this step, as shown in FIG. 6, a chromium film 9 is laminated on the water-repellent film 6 covering the ink discharge back surface 5 and the funnel-shaped opening 8.

Although a chromium film is used in this embodiment, other metal films or oxide films may be used, and the film thickness is desirably 0.1 μm or more.

In this way, as shown in FIG. 6, the position of the water-repellent coating 6 exposed inside the ink ejection hole 4
That is, a nozzle plate for an ink jet printer head having a fixed entrance position is completed.

In order to confirm the effect of the first embodiment of the present invention, as a comparative sample, a hole was formed by punching the metal plate-shaped member 1 from the side corresponding to the ink ejection back surface 5 with the punch shown in FIG. The photosensitive resin film is pressed against the ink discharge back surface 5 and a part of the film is
As a result of performing a Teflon eutectoid plating, removing a film and performing a heat treatment on a nozzle plate, and performing a cross-sectional SEM observation of the ink discharge holes 4,
In the nozzle plate according to the present invention, the distance from the ink ejection surface 3 of the Teflon eutectoid plating which entered the ink ejection holes 4 was 10 μm in all the ink ejection holes 4. However,
In the nozzle plate of the comparative sample, it was confirmed that the distance from the ink ejection surface 3 of the Teflon eutectoid plating that entered the inside of the ink ejection hole 4 was irregularly varied in the range of 5 μm to 20 μm.

A head was assembled using the nozzle plate of the present invention and the nozzle plate of the comparative sample, a pigment-based ink was injected, and a continuous discharge test was performed. As a result, the head using the nozzle plate of the present invention was stable. However, in the head using the nozzle plate of the comparative sample, the ink ejection direction was bent, or a phenomenon that the ink was not ejected at all along the way occurred.

As can be seen from the above results, in the method of manufacturing a nozzle plate for an ink jet printer head according to the present invention, the position where the liquid repellent coating 6 enters the inside of the ink discharge hole 4 is precisely controlled, and the meniscus position is constant. It was confirmed that stable ejection of ink was enabled.

Next, a method of manufacturing a nozzle plate for an ink jet printer head according to a second embodiment of the present invention will be described. 7 to 11 are cross-sectional views illustrating a method of manufacturing a nozzle plate for an ink jet printer head according to a second embodiment of the present invention, in which the ink ejection holes are enlarged. Hereinafter, description will be made with reference to the perspective view of FIG. 1 and the process sectional views of FIGS. 7 to 11.

In order to produce the nozzle plate for an ink jet printer head according to the present invention, a length of 30 mm, a width of 15 mm and a thickness of 0.1 mm as shown in FIG.
A hole shown in FIG. 2 is punched from the side of the flat metal member 1 having a diameter of 5 mm, which corresponds to the ink ejection back surface 5, and burrs formed on the ink ejection surface 3 are removed by polishing and chemically etching the ink ejection surface 3. .

By the above steps, as shown in FIG. 7, the diameter of the ink discharge surface 3 of the ink discharge hole 4 is 40 microns, the diameter of the ink discharge back surface 5 is 100 microns, and the length of the cylindrical opening 7 is An ink ejection hole 4 of 10 microns is formed. Although one ink ejection hole is illustrated in the drawing, the punches shown in FIG.
It is possible to form a large number of ink ejection holes at a time as shown in FIG.

Next, as shown in FIG. 8, a protective film 11 is adhered to the ink ejection back surface 5. As this protective film, a dry film resist is suitable. Thereafter, in order to form a water-repellent coating 6 on the nozzle plate 1, Teflon eutectoid plating is performed under the same conditions as in the first embodiment, and as shown in FIG. Is formed.

The water-repellent coating 6 may be made of a material other than Teflon eutectoid plating, and may be a fluororesin or a silicone resin.

Next, as shown in FIG.
Is removed by a mechanical or chemical etching method. In this state, the ink ejection back surface 5 is exposed in a state where the surface of the metal plate-shaped member 1 is solid.
Next, a titanium film 9 is formed by sputtering from a direction perpendicular to the ink discharge back surface 5. The film thickness was 0.2 microns. By this step, as shown in FIG. 11, a titanium film 9 is laminated on the water-repellent coating 6 covering the ink ejection back surface 5 and the funnel-shaped opening 8.

At this time, since the titanium film 9 to be formed is formed directly on the ink ejection back surface 5 composed of the surface of the metal plate-shaped member 1, the adhesion of the titanium film 9 is improved. Film 9 when bonding the ink flow path with the ink
This also has the effect of improving the adhesion between the ink and the components on the ink flow path side.

In this manner, a nozzle plate for an ink jet printer head in which the exposed position of the water-repellent coating 6 inside the ink ejection hole 4, that is, the entry position is the same as in the first embodiment is completed.

In order to confirm the effect of the second embodiment of the present invention, as in the first embodiment, the cross section S
As a result of EM observation, in the nozzle plate according to the present invention, the distance from the ink ejection surface 3 of the Teflon eutectoid plating that entered the ink ejection holes 4 was 10 μm in all the ink ejection holes 4.

A head was assembled using the nozzle plate of the present invention and the nozzle plate of the comparative sample manufactured in the first embodiment, a pigment-based ink was injected, and a continuous discharge test was performed. The head using the nozzle plate ejected stably, but the head using the nozzle plate of the comparison sample caused a phenomenon in which the ejection direction of the ink was bent or the ink was not ejected at all along the way.

Further, as a result of performing a destructive test by peeling off the nozzle plate after assembling a head using the nozzle plate manufactured in the first embodiment and the nozzle plate manufactured in the second embodiment according to the present invention, The nozzle plate manufactured in the first embodiment was peeled off from the interface between the nozzle plate main body and the chromium film 9 with a force of about 10 kgf.
It did not peel off even when pulled with a force of 0 kgf, and it was confirmed that the adhesiveness to the components on the ink flow path side was better than that of the nozzle plate manufactured in the first embodiment. However, there is no problem in performance and life as a head even with the nozzle plate manufactured in the first embodiment.

As can be seen from the above results, in the method of manufacturing a nozzle plate for an ink jet printer head according to the present invention, the position where the liquid-repellent coating 6 enters the inside of the ink ejection hole 4 is precisely controlled, and the meniscus position is constant. It was confirmed that stable ejection of ink was enabled.

[0042]

As is apparent from the above embodiments, in the method of manufacturing a nozzle plate for an ink jet printer head according to the present invention, the ink discharge holes are formed by pressing the back surface of the metal plate member, and then the ink discharge holes are formed. The entire nozzle plate including the inner surface is coated with a water-repellent coating, and the back surface of the metal plate-shaped member, that is, an oxide or a metal is vapor-deposited, sputtered, or ion-plated from a direction perpendicular to the ink ejection back surface. By forming the film, the position where the liquid-repellent coating enters the inside of the ink ejection hole can be precisely controlled, and the meniscus position can be kept constant.
As a result, stable ejection of ink becomes possible, and there is an effect of improving the reliability of the ink jet printer.

[Brief description of the drawings]

FIG. 1 is a perspective external view showing a structure and a surface treatment method of a thin plate-shaped nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a punch for forming a hole by press working used in a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a method for manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a method for manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

FIG. 11 is a cross-sectional view illustrating a method of manufacturing a nozzle plate for an inkjet printer head according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate-shaped member 2 Nozzle plate 3 Ink ejection surface 4 Ink ejection hole 5 Ink ejection back surface 6 Water-repellent coating 7 Portion opened in a funnel shape 8 Portion opened in a funnel shape 9 Oxide or metal film 11 Protection film 21 tube Tip

Claims (3)

[Claims] 1. A step of punching an ink discharge hole from a back surface of a metal plate member by press working, a step of coating a water-repellent coating on the entire metal plate member, and a step of coating a back surface of the metal plate member. Forming a film of an oxide or a metal. 2. The step of punching an ink discharge hole from the back surface of a metal plate member by press working is a plastic working by a punch having a cylindrical front end portion and a conical rear end portion. A method for manufacturing a nozzle plate for an inkjet printer head according to claim 1. 3. The nozzle for an ink jet printer head according to claim 1, wherein the step of forming an oxide or a metal on the back surface of the metal plate member is a method by vapor deposition, sputtering, or ion plating. Plate manufacturing method.